Bananas Foster Layer Cake with Rum Caramel Frosting

Name: Bananas Foster Layer Cake with Rum Caramel Frosting
Prep time: 55 min
Cook time: 35 min
Total time: 2 h 30 min
Yield: one 9-inch three-layer cake
Cuisine: American
Ingredients: 360 g all-purpose flour (about 3 cups, spooned and leveled); 2 tsp baking powder; 0.75 tsp baking soda; 1 tsp ground cinnamon; 0.25 tsp freshly grated nutmeg; 0.75 tsp fine sea salt; 170 g unsalted butter, at room temperature (3/4 cup or 1.5 sticks); 200 g dark brown sugar, packed (1 cup); 150 g granulated sugar (3/4 cup); 3 large eggs, at room temperature; 2 tsp pure vanilla extract; 360 g very ripe mashed banana (about 3 large bananas, roughly 1.5 cups); 120 ml sour cream, at room temperature (1/2 cup); 60 ml whole milk, at room temperature (1/4 cup); 30 ml dark rum (2 tablespoons); For the Rum Caramel Sauce; 200 g granulated sugar (1 cup); 60 ml water (1/4 cup); 120 ml heavy cream, warm (1/2 cup); 56 g unsalted butter, cubed (4 tablespoons); 45 ml dark rum (3 tablespoons); 0.5 tsp fine sea salt; For the Rum Caramel Buttercream; 340 g unsalted butter, at room temperature (1.5 cups or 3 sticks); 480 g powdered sugar, sifted (4 cups); 120 ml cooled rum caramel sauce (reserve the rest for drizzling, about 1/2 cup from above); 2 tbsp heavy cream; 0.25 tsp fine sea salt; For the Caramelized Banana Filling; 2 medium firm-ripe bananas, sliced into 1/4-inch rounds

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There is something almost theatrical about Bananas Foster. It was born in 1951 at Brennan’s Restaurant in New Orleans, where a waiter would wheel a cart to your table, ignite a pan of brown sugar, butter, and rum, and ladle the flaming caramel over scoops of vanilla ice cream. The whole room would glow for a moment. This cake is an attempt to capture that same warmth, that same caramelized, rum-kissed magic, in something you can slice and serve at a birthday table, a Sunday dinner, or a quiet Tuesday when you need a reason to celebrate.

What sets this version apart is a three-part commitment to the Bananas Foster flavor profile. First, the cake layers are made with mashed very ripe bananas and dark brown sugar, which gives the crumb a deep, almost toffee-like sweetness and a tender, moist texture that keeps for days. Second, a quick stovetop rum caramel sauce is folded directly into the buttercream, so every bite of frosting carries that complex, slightly boozy depth rather than just tasting of powdered sugar. Third, caramelized banana slices are layered between each tier, giving you little pockets of soft, jammy fruit that echo the original dessert in every single bite.

This is a medium-difficulty bake, best suited for someone who has made a layer cake before and is comfortable working with caramel. The individual steps are straightforward, but there are a few of them, and a little organization goes a long way. Read the recipe all the way through before you start, and know that almost everything can be made ahead. This cake is absolutely perfect for a special birthday, a dinner party where you want to impress, or any occasion that deserves something a little more memorable than ordinary.

Prep: 55 minutesTotal: 2 hours 30 minutes (including cooling time)Yield: one 9-inch three-layer cakeDifficulty: ★★☆ IntermediateOccasion: Special Occasion

✓ Vegetarian

Servings:

12

servings

Ingredients

360 gall-purpose flour (about 3 cups, spooned and leveled)
2 tspbaking powder
0.75 tspbaking soda
1 tspground cinnamon
0.25 tspfreshly grated nutmeg
0.75 tspfine sea salt
170 gunsalted butter, at room temperature (3/4 cup or 1.5 sticks)
200 gdark brown sugar, packed (1 cup)
150 ggranulated sugar (3/4 cup)
3 largeeggs, at room temperature
2 tsppure vanilla extract
360 gvery ripe mashed banana (about 3 large bananas, roughly 1.5 cups)
120 mlsour cream, at room temperature (1/2 cup)
60 mlwhole milk, at room temperature (1/4 cup)
30 mldark rum (2 tablespoons)
—For the Rum Caramel Sauce
200 ggranulated sugar (1 cup)
60 mlwater (1/4 cup)
120 mlheavy cream, warm (1/2 cup)
56 gunsalted butter, cubed (4 tablespoons)
45 mldark rum (3 tablespoons)
0.5 tspfine sea salt
—For the Rum Caramel Buttercream
340 gunsalted butter, at room temperature (1.5 cups or 3 sticks)
480 gpowdered sugar, sifted (4 cups)
120 mlcooled rum caramel sauce (reserve the rest for drizzling, about 1/2 cup from above)
2 tbspheavy cream
0.25 tspfine sea salt
—For the Caramelized Banana Filling
2 mediumfirm-ripe bananas, sliced into 1/4-inch rounds
28 gunsalted butter (2 tablespoons)
50 gdark brown sugar, packed (1/4 cup)
15 mldark rum (1 tablespoon)
—Pinch of cinnamon for the filling pan

Ingredient Substitutions

dark rum

1 tsp rum extract plus enough orange juice or apple juice to make up the same volume. The flavor will be less complex but still delicious.
Bourbon makes a wonderful non-rum alternative and leans into the caramel notes beautifully.

sour cream

Full-fat plain Greek yogurt in an equal amount works perfectly and keeps the crumb just as tender.
Full-fat creme fraiche is a rich, slightly tangy substitute that works beautifully here.

eggs

For a whole egg, use 1 flax egg (1 tablespoon ground flaxseed mixed with 3 tablespoons water, rested 5 minutes). The cake will be slightly denser but still moist given the banana content.

unsalted butter (in cake and buttercream)

Salted butter can be used throughout. Simply omit the added salt in each component and taste as you go.
Vegan block-style butter (such as Miyoko’s) works in both the cake and frosting, though the buttercream may be slightly softer. Chill briefly before frosting if needed.

whole milk

Any plant-based milk (oat, almond, or soy) works in equal measure with minimal impact on the final cake.
Additional sour cream thinned slightly will also work and adds a little more tang.

dark brown sugar (in cake)

Light brown sugar can be used but will produce a slightly less intense caramel flavor. Add 1 extra teaspoon of molasses per cup if you have it on hand.

Instructions

🔧 Equipment

🟫three 9-inch round cake pans (or one 9×13-inch pan, or two 12-cup muffin tins)

📄parchment paper

⚡stand mixer or hand mixer with bowl

🥣medium heavy-bottomed saucepan

🌡️candy thermometer (optional but helpful)

🥣heatproof mixing bowls

🍳medium skillet

🔵wire cooling racks

🍴offset spatula

🎂large piping bag with round or star tip (for cupcake method)

⚖️kitchen scale

🖌️pastry brush

🍴rubber spatula

Prep: 55 minutes
Bake: 30 to 35 minutes at 350°F (175°C)
Total: 2 hours 30 minutes

Preheat your oven to 350°F (175°C). Grease three 9-inch round cake pans with butter or nonstick spray, then line the bottoms with parchment paper circles and lightly flour the sides. Set aside.
Make the rum caramel sauce first so it has time to cool. In a medium heavy-bottomed saucepan, combine 200g sugar and 60ml water over medium heat. Stir gently just until the sugar dissolves, then stop stirring entirely and let the mixture cook undisturbed until it turns a deep amber color, like dark honey, about 10 to 14 minutes. Keep a close eye on it near the end as it can go from perfect to burnt quickly. Remove from heat and carefully pour in the warm heavy cream (it will bubble vigorously). Stir in the butter, then the rum and salt. Pour into a heatproof bowl and let cool completely to room temperature, at least 45 minutes.
While the caramel cools, make the cake batter. In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, nutmeg, and salt. In a large bowl or the bowl of a stand mixer fitted with the paddle attachment, beat the butter, dark brown sugar, and granulated sugar on medium-high speed until very light and fluffy, about 4 to 5 minutes. Scrape down the bowl. Add the eggs one at a time, beating for 30 seconds after each addition. Beat in the vanilla extract and the mashed banana. The mixture may look slightly curdled at this stage, which is normal.
Add the flour mixture in three additions, alternating with the combined sour cream, milk, and rum, beginning and ending with the flour. Mix on low speed after each addition until just combined. Do not overmix. Scrape the bottom of the bowl with a spatula to make sure no flour streaks remain.
Divide the batter evenly among the three prepared pans (a kitchen scale is helpful here, roughly 420g per pan). Smooth the tops with an offset spatula. Bake for 30 to 35 minutes, until the tops are golden brown, the cakes have pulled slightly away from the sides of the pans, and a toothpick inserted in the center comes out with just a few moist crumbs. Rotate the pans halfway through baking if your oven has hot spots.
Cool the cakes in their pans on a wire rack for 15 minutes, then turn them out, peel off the parchment, and let cool completely on the rack before frosting. Do not rush this step; a warm cake will melt the buttercream.
Make the caramelized banana filling. In a medium skillet over medium heat, melt the butter and brown sugar together, stirring until the sugar dissolves and begins to bubble. Add the banana slices in a single layer and cook for 1 to 2 minutes per side, until golden and caramelized. Add the rum and a pinch of cinnamon, let it sizzle for 30 seconds, then remove from heat. Transfer to a plate and cool completely.
Make the rum caramel buttercream. Beat the softened butter on medium-high speed for 3 to 4 minutes until very pale and fluffy. Reduce speed to low and gradually add the powdered sugar, mixing until incorporated. Add the cooled rum caramel sauce, heavy cream, and salt. Increase speed to medium-high and beat for another 2 minutes until smooth, silky, and spreadable. If the frosting is too soft, refrigerate for 15 minutes before using.
Assemble the cake. Place the first cake layer on a serving plate or cake board. Spread a generous layer of buttercream, then arrange half the caramelized banana slices evenly over the frosting. Top with the second cake layer and repeat. Place the third cake layer on top, cut side down. Apply a thin crumb coat of frosting all over the cake and refrigerate for 20 minutes to set. Then apply the final layer of frosting. Drizzle the remaining rum caramel sauce over the top, letting it drip down the sides. Garnish with a few fresh banana slices just before serving if desired.

Prep: 55 minutes
Bake: 35 to 40 minutes at 350°F (175°C)
Total: 1 hour 45 minutes

This method simplifies the recipe into a relaxed, crowd-friendly sheet cake that is perfect for casual gatherings. You still get all the flavors without the layering and crumb-coating steps.

Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan with butter and line it with parchment paper, leaving an overhang on the long sides for easy lifting.
Make the rum caramel sauce and let it cool as described in the oven method above. You will use roughly half in the frosting and drizzle the rest over the finished cake.
Prepare the full cake batter following the same method as the oven recipe. Pour all of the batter into the prepared pan and smooth the top evenly with an offset spatula.
Bake for 35 to 40 minutes, until a toothpick inserted in the center comes out with just a few moist crumbs and the top is deep golden brown. The cake will puff and then settle as it bakes. Cool completely in the pan on a wire rack, at least 1 hour.
Make the caramelized banana filling and the rum caramel buttercream as directed. Spread the buttercream generously over the cooled cake directly in the pan, then arrange the cooled caramelized banana slices over the top. Drizzle with the remaining rum caramel sauce in a zigzag pattern. Slice directly from the pan into 12 to 16 squares and serve. The sheet cake format also makes it very easy to transport to potlucks or parties.

Prep: 55 minutes
Bake: 18 to 22 minutes at 350°F (175°C)
Total: 1 hour 30 minutes

The full batter makes approximately 24 standard cupcakes. This format is ideal for parties and events where individual portions are easier to serve. Each cupcake can be topped with a single caramelized banana slice for a beautiful presentation.

Preheat your oven to 350°F (175°C). Line two standard 12-cup muffin tins with cupcake liners. Do not skip the liners; the moist banana batter can stick to even well-greased pans.
Make the rum caramel sauce and let it cool completely before making the frosting. The full caramel recipe is used here, with half going into the buttercream and the rest used for individual drizzles over the finished cupcakes.
Prepare the full cake batter as described in the oven method. Fill each cupcake liner about two-thirds full, roughly 55 to 60g of batter per cup. Overfilling will cause the tops to spread flat rather than dome.
Bake for 18 to 22 minutes, until a toothpick inserted in the center of a cupcake comes out clean and the tops are lightly golden and spring back when gently pressed. Do not overbake; these cupcakes are best slightly moist at the center. Cool in the tins for 5 minutes, then transfer to a wire rack to cool completely.
Make the caramelized banana filling and rum caramel buttercream as directed. Transfer the buttercream to a piping bag fitted with a large round or star tip. Pipe a generous swirl onto each cooled cupcake. Top each with one or two pieces of caramelized banana and drizzle lightly with the remaining caramel sauce. Serve within a few hours of assembly for the best texture, as the banana slices will soften over time.

Nutrition Per Serving

Per 1 serving (makes one 9-inch three-layer cake)

685Calories

88gCarbs

64gSugar

34gFat

6gProtein

Why This Recipe Works

The foundation of this cake’s moist, tender crumb is the combination of very ripe bananas and dark brown sugar. As bananas ripen, their starches convert to simple sugars and their cell walls break down, releasing natural moisture and intensifying their flavor. This acts as a natural humectant in the batter, meaning the cake actively holds onto moisture during and after baking, which is why a banana cake stays so soft for days. The dark brown sugar, which contains more molasses than its light counterpart, adds a second layer of caramel-like depth and also contributes to a slightly fudgy crumb thanks to molasses’s hygroscopic properties.

The rum caramel sauce requires a moment of patience, but understanding the process makes it much less intimidating. When sugar is heated with water, the water first helps the sugar dissolve evenly to prevent crystallization. As the water evaporates and the temperature climbs above 320°F (160°C), the sugar molecules begin to break apart and recombine into hundreds of new flavor compounds through a process called pyrolysis. This is what gives caramel its complex, bittersweet, almost nutty flavor. Adding warm cream rather than cold prevents the caramel from seizing or hardening from the sudden temperature shock, and the butter emulsifies into the sauce for a glossy, velvety finish. The rum goes in last, off the heat, so its more delicate aromatic compounds are not driven off by high temperatures.

Using sour cream alongside mashed banana in the batter serves two purposes. The fat in the sour cream tenderizes the gluten strands, and its acidity reacts with the baking soda to produce carbon dioxide bubbles, giving the cake its lift and an open, tender crumb. This acidic environment also helps keep the banana flavor bright and prevents it from becoming muddy or overly sweet. The alternating method of adding flour and liquid (dry, wet, dry, wet, dry) is a classic technique that prevents the batter from becoming tough by never allowing the gluten to develop too much at any one addition.

Baker’s Tips

Bring all refrigerated ingredients, including butter, eggs, sour cream, and milk, to room temperature before starting. Cold butter will not cream properly, and cold eggs can cause the batter to curdle.
The riper your bananas, the better. Look for bananas with fully brown, spotted skins. If yours are not quite there, place unpeeled bananas on a baking sheet and roast at 300°F (150°C) for 15 to 20 minutes until the skins are black. Cool before using.
Do not stir your caramel once it starts boiling. Stirring encourages sugar crystals to form, which will cause the whole batch to seize into a grainy mess. Swirl the pan gently if you need to even out the color.
A candy thermometer is helpful for the caramel but not essential. Watch for a deep amber color that looks like dark honey or aged whiskey, not pale gold and not dark brown. It happens fast at the end, so stand at the stove.
To get perfectly even cake layers, use a kitchen scale to divide the batter equally among the pans. Even layers make for a more stable, professional-looking finished cake.
The buttercream should be a smooth, spreadable consistency. If it looks greasy or curdled, the butter was likely too warm. Chill the bowl for 10 minutes and beat again. If it is too stiff, add heavy cream a tablespoon at a time.
Apply a thin crumb coat of frosting over the assembled layers and refrigerate for 20 minutes before the final coat. This seals in any loose crumbs and makes the finished cake look clean and polished.

Variations

Chocolate Bananas Foster: Replace 40g of the flour with Dutch-process cocoa powder and add 60g of melted dark chocolate to the batter with the eggs. The chocolate and rum caramel combination is extraordinary.
Spiced version: Add 1/4 teaspoon each of ground cardamom and allspice to the dry ingredients for a more complex, warming spice profile that plays beautifully against the banana.
Banana rum upside-down cake: Arrange brown-sugar-coated banana slices in the bottom of a buttered 9-inch round pan before adding the batter. Bake as a single layer for 35 to 40 minutes and invert while still warm for a stunning presentation.
Non-alcoholic version: Replace all rum in the recipe with 1 teaspoon of rum extract per tablespoon of rum, plus enough pineapple juice or apple juice to make up the liquid volume. The flavor is slightly different but still wonderful.

Troubleshooting & FAQ

My caramel seized up and turned grainy or solid. What happened?

This is crystallization, and it usually happens for one of three reasons: sugar crystals on the sides of the pan fell into the mixture, the caramel was stirred after it came to a boil, or the cream was added too cold and caused the sugar to shock and seize. To salvage it, add a tablespoon of water and heat gently while stirring until it dissolves back into a smooth sauce. To prevent it next time, use a pastry brush dipped in water to wash down the sides of the pan, avoid stirring once boiling, and warm your cream before adding it.

My cake layers came out dense and gummy rather than light and fluffy. What went wrong?

The most likely culprits are overmixing the batter after the flour was added (which develops tough gluten), using bananas that were too wet (very large or watery bananas can throw off the liquid balance), or underbaking. Mix the batter only until the flour just disappears and check doneness with a toothpick. If you suspect wet bananas, drain off any excess liquid from the mashed fruit before measuring.

My rum caramel buttercream is too soft and will not hold its shape on the cake.

This happens when the caramel sauce was still warm when added to the frosting, or when the kitchen is very warm. Transfer the buttercream to the refrigerator for 15 to 20 minutes, then re-beat briefly. Make sure your caramel is fully cooled and at room temperature, not just warm to the touch, before incorporating it into the butter. On a hot day, work in a cool kitchen and chill the assembled cake before the final frosting coat.

The caramelized bananas for the filling turned to mush in the skillet.

This usually means the bananas were too ripe. For the filling, use firm-ripe bananas, yellow with just a touch of spotting, rather than the very soft, heavily speckled bananas used in the cake batter. Soft bananas will break down the moment they hit the hot pan. Also, do not crowd the pan or stir too much; let them sit and caramelize before gently flipping.

My finished cake is leaning or the layers are sliding. How do I fix it?

Sliding layers almost always mean the cake was not fully cooled before assembly, the buttercream was too soft, or the caramelized banana filling created a slippery surface without enough frosting to anchor it. Make sure layers are completely cold, the buttercream is firm enough to hold its shape, and that you pipe a border of buttercream around the edge of each layer before adding the banana filling. This border acts as a dam and keeps everything in place. If the cake is already assembled and leaning, refrigerate it for 30 minutes to firm everything up.

Storage & Make-Ahead

Storage: Store the finished cake covered at room temperature for up to 2 days, or refrigerate for up to 5 days. Bring refrigerated slices to room temperature for 30 minutes before serving for the best texture. The caramelized banana filling is best made fresh, as the bananas will soften and discolor over time. Do not add fresh banana garnish until just before serving.
Make-Ahead: The cake layers can be baked up to 2 days ahead, wrapped tightly in plastic wrap, and stored at room temperature, or frozen for up to 2 months. The rum caramel sauce can be made up to 2 weeks ahead and stored in a jar in the refrigerator; rewarm gently before using in the buttercream. The buttercream can be made up to 3 days ahead and refrigerated in an airtight container. Re-beat it with a splash of cream to restore its texture before frosting. Make the caramelized banana filling the day of assembly for best results.