There is something deeply comforting about a fruit crisp straight from the oven, the edges bubbling with sweet fruit juices and the topping crackling with that irresistible golden crunch. This Keto Peach Crisp captures every bit of that summer magic — the fragrant, tender peaches, the warmth of cinnamon and vanilla, the buttery, nutty topping that shatters just slightly when your spoon breaks through. Served warm with a spoonful of cold whipped cream or a scoop of sugar-free vanilla ice cream, it is the kind of dessert that makes a quiet weeknight feel like a special occasion.
What sets this crisp apart is the topping. Rather than leaning entirely on almond flour (which can turn dense and greasy), we use a careful blend of almond flour, roughly chopped almonds, and a small amount of certified gluten-free rolled oats. The oats are kept in modest quantity to stay keto-friendly while contributing the classic hearty chew and rustic texture a proper crisp deserves. The entire recipe is sweetened with allulose, a rare sugar found naturally in figs and raisins that behaves remarkably like real sugar in baking. It browns, it caramelizes, and it dissolves into the peach juices to create a glossy, jammy filling without any blood sugar spike.
This recipe sits comfortably in the easy-to-medium difficulty range. If you can slice a peach and stir a few ingredients together, you can make this. It is ideal for anyone following a keto or low-sugar lifestyle who still wants to serve something genuinely impressive, and it is equally perfect for sharing with guests who have no dietary restrictions at all. Nobody will guess it is sugar-free.
8
servings
Ingredients
- Filling
- 900 gfresh peaches, peeled and sliced about 1/2-inch thick (about 6 to 7 medium peaches, or 2 lbs)
- 60 gallulose (about 1/4 cup)
- 15 mlfresh lemon juice (about 1 tbsp)
- 1 tsppure vanilla extract
- 1 tspground cinnamon
- 10 garrowroot powder or tapioca starch (about 1 tbsp), to thicken the filling
- 100 gblanched almond flour (about 1 cup, spooned and leveled)
- 40 gcertified gluten-free rolled oats (about 1/3 cup)
- 60 graw almonds, roughly chopped (about 1/2 cup)
- Topping
- 80 gallulose (about 1/3 cup)
- 1 tspground cinnamon
- 0.25 tspground ginger
- 0.5 tspfine sea salt
- 85 gcold unsalted butter, cut into small cubes (about 6 tbsp)
- —Pinch of freshly grated nutmeg
Ingredient Substitutions
Instructions
🔧 Equipment
- Preheat your oven to 350°F (175°C). Lightly butter or grease a 9-inch square or equivalent 2-quart baking dish.
- Make the filling: In a large bowl, combine the sliced peaches, 60g allulose, lemon juice, vanilla extract, 1 tsp cinnamon, nutmeg, and arrowroot powder. Toss gently until every peach slice is coated. Pour the filling into the prepared baking dish and spread into an even layer.
- Make the topping: In a medium bowl, whisk together the almond flour, rolled oats, chopped almonds, 80g allulose, 1 tsp cinnamon, ground ginger, and salt. Add the cold butter cubes. Using your fingertips, pinch and press the butter into the dry mixture until the topping resembles coarse, clumpy crumbs with pea-sized and almond-sized butter pieces throughout. Do not overwork — those butter chunks create steam pockets that make the topping flaky and crisp.
- Scatter the topping evenly over the peach filling, covering the fruit completely but not packing it down. A loose, uneven layer gives the best crunch.
- Bake on the center rack for 35 to 40 minutes, until the topping is deep golden brown and the peach filling is visibly bubbling at the edges. Allulose browns faster than sugar, so begin checking at the 30-minute mark. If the topping is browning too quickly, tent loosely with foil and continue baking.
- Remove from the oven and let rest for at least 10 to 15 minutes before serving. The filling continues to thicken as it cools. Serve warm with sugar-free whipped cream or a scoop of keto vanilla ice cream.
- Halve all ingredient quantities for a 4-serving crisp. Lightly grease a 7-inch round cake pan or a 6-inch oven-safe dish that fits inside your air fryer basket.
- Prepare the peach filling exactly as in the oven method, tossing sliced peaches with allulose, lemon juice, vanilla, cinnamon, nutmeg, and arrowroot powder. Spread evenly in the greased pan.
- Make the topping using the halved quantities. Work the cold butter into the dry mixture with your fingertips until clumpy. Scatter loosely over the peach layer.
- Preheat the air fryer to 320°F (160°C) for 3 minutes. Place the pan in the basket. Cook for 22 to 25 minutes. Check at the 18-minute mark — because allulose caramelizes quickly and the air fryer circulates heat intensely, cover loosely with a small square of foil if the topping is browning faster than desired.
- The crisp is done when the topping is golden and fragrant and the filling is bubbling. Use oven mitts to remove the pan carefully. Rest for 10 minutes before serving directly from the pan.
- Lightly grease the insert of a 4-quart or 6-quart slow cooker with butter or coconut oil. Prepare the peach filling by tossing sliced peaches with 60g allulose, lemon juice, vanilla, 1 tsp cinnamon, nutmeg, and arrowroot powder. Add to the slow cooker insert and spread evenly.
- Make the topping: In a bowl, combine almond flour, oats, chopped almonds, 80g allulose, 1 tsp cinnamon, ginger, and salt. Work in the cold butter cubes until the mixture is clumpy and resembles coarse crumbs. Scatter the topping over the peaches.
- Lay a double layer of paper towels or a clean kitchen towel directly under the slow cooker lid before sealing. This absorbs condensation that would otherwise drip onto the topping and make it soggy. Place the lid on top of the towel.
- Cook on High for 2.5 to 3 hours. The filling should be bubbling and the peaches completely tender. The topping will be set but pale and soft.
- For a crispier topping, carefully transfer the filling and topping to an oven-safe baking dish and place under the broiler on the top rack for 2 to 3 minutes, watching closely, until golden. Alternatively, serve as-is and celebrate the extra-saucy, tender filling. Rest 10 minutes before serving.
Nutrition Per Serving
Per 1 serving (makes one 9-inch square or round baking dish, serving 8)
Sweetener: allulose
Why This Recipe Works
Allulose is the real star of this recipe, and it is worth understanding why it outperforms other keto sweeteners here. Allulose is a monosaccharide that behaves almost identically to sucrose in wet, high-heat applications: it dissolves cleanly, caramelizes at similar temperatures, and creates that glossy, syrupy consistency in the fruit filling without any gritty texture. Allulose, by contrast, can recrystallize as it cools, leaving a sandy mouthfeel in fruit-based fillings. Monk fruit on its own does not caramelize or brown. Allulose does both, which is why the topping turns that deep, appetizing gold and the filling becomes glossy and jammy rather than watery.
The arrowroot powder in the filling is doing important structural work. Fresh peaches release a significant amount of liquid as they bake, and without a thickener, the filling would be a soup beneath the topping. Arrowroot thickens at a lower temperature than cornstarch and produces a clearer, more delicate gel that does not cloud the beautiful peach juices. One tablespoon is precisely enough for this quantity of fruit: enough to hold the filling together as it cools, but not so much that it becomes gluey or starchy.
In the topping, the combination of cold butter, almond flour, oats, and whole chopped almonds creates three distinct textures working together. The almond flour provides a fine, sandy base that holds the topping together. The rolled oats absorb a little of the butter and puff slightly during baking, contributing chew. The chopped almonds stay relatively sturdy and add genuine crunch. Cold butter is non-negotiable: as it heats in the oven, the water in the butter converts to steam, creating small pockets that make the topping light and crumbly rather than dense and greasy. If the butter melts before baking, those pockets never form and the topping will be flat and oily.
Baker’s Tips
- Peel peaches easily by scoring an X on the bottom, dropping them in boiling water for 30 seconds, then transferring to an ice bath. The skins slip right off.
- Allulose browns faster than regular sugar. Begin checking the crisp at the 30-minute mark and tent with foil if the topping is darkening before the filling is bubbling.
- Do not skip the resting time after baking. The arrowroot-thickened filling needs 10 to 15 minutes off the heat to fully set. A crisp served immediately from the oven will be runny.
- Keep your butter genuinely cold. If your kitchen is warm, freeze the cubed butter for 10 minutes before working it into the topping.
- For extra-deep flavor, toast the chopped almonds in a dry skillet over medium heat for 3 to 4 minutes until fragrant before adding them to the topping mixture.
- The net carb count per serving is approximately 15g (total carbs minus fiber), making this suitable for most moderate keto approaches.
Variations
- Peach and raspberry: Replace 200g of peaches with fresh or frozen raspberries for a tart, jewel-bright filling with beautiful color.
- Spiced cardamom version: Add 1/2 tsp ground cardamom and a pinch of black pepper to the filling for a warm, exotic twist that pairs beautifully with peaches.
- Dairy-free and vegan: Use refined solid coconut oil in place of butter and confirm your sweetener is vegan-certified. All other ingredients are naturally plant-based.
- Extra nutty topping: Replace the rolled oats with 40g of roughly chopped pecans and add 2 tbsp unsweetened shredded coconut for a topping with deeper caramel-like flavor.
Troubleshooting & FAQ
My topping turned very dark or almost burnt before the filling was bubbling. What happened?
My peach filling is watery and never thickened properly. How do I fix it?
The topping is soft and soggy, not crispy. What went wrong?
I used allulose instead of allulose and now the filling has a gritty texture as it cools. Is it ruined?
My peaches were very ripe and released a huge amount of liquid. The whole crisp is soupy.
Storage & Make-Ahead
- Storage: Store covered tightly with plastic wrap or in an airtight container in the refrigerator for up to 4 days. The topping will soften overnight — reheat individual portions in a 350°F oven for 8 to 10 minutes, or in an air fryer at 320°F for 4 to 5 minutes to restore crunch. Not recommended for freezing once assembled, as the peach filling becomes watery on thawing.
- Make-Ahead: The peach filling can be assembled and refrigerated (unbaked) up to 24 hours ahead, covered tightly. The topping can be made and stored in an airtight container in the refrigerator for up to 3 days, or frozen for up to 1 month. Assemble and bake straight from the refrigerator, adding 5 minutes to the bake time.
