This Blueberry Peach Crumble is a quick high-protein dessert made with fresh blueberries and peaches under a sweet, buttery crumble topping. Perfect for a healthy weeknight treat or simple picnic…

Ingredients

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Instructions

Step 1

Preheat your oven to 375°F (190°C). While the oven heats, select a 9×9-inch baking dish or a similar 2-quart casserole dish. Lightly grease the dish with a small amount of butter or non-stick spray. This ensures the bubbling fruit juices won’t stick and makes cleanup a breeze. The preheating step is crucial: a properly heated oven ensures the crumble topping browns evenly and the fruit filling thickens without becoming mushy.

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Step 2

Prepare the fruit filling: In a large mixing bowl, gently combine the fresh blueberries and sliced peaches. Drizzle with lemon juice, then add the granulated sugar and cornstarch. Toss everything together with a spatula until the fruit is evenly coated. The lemon juice brightens the flavor and prevents the fruit from browning, while the cornstarch acts as a thickener, absorbing the juices released during baking to create a luscious, jammy consistency. Let the mixture sit for 5 minutes to allow the cornstarch to activate.

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Step 3

Transfer the fruit mixture to the prepared baking dish, spreading it into an even layer. Set aside while you prepare the crumble topping.

Step 4

Make the crumble topping: In a separate medium bowl, whisk together the rolled oats, all-purpose flour, brown sugar, salt, and ground cinnamon. If you’re using protein powder, add it now and whisk to combine. The oats provide a hearty texture and fiber, while the flour gives structure. The brown sugar adds moisture and a deep caramel-like sweetness. Cinnamon complements the fruit with warmth.

Step 5

Add the cold butter cubes to the dry mixture. Using a pastry cutter, two forks, or your fingertips, work the butter into the dry ingredients until the mixture resembles coarse crumbs with some pea-sized butter pieces remaining. It’s important to keep the butter cold; if it softens, pop the bowl in the fridge for 5 minutes. Cold butter creates a tender, flaky crumble that bakes into golden clusters. If using nuts, fold them in at this stage.

Step 6

Sprinkle the crumble topping evenly over the fruit filling. Do not press it down; leave it loose so it can crisp up during baking. Place the dish on a baking sheet to catch any drips, then bake in the preheated oven for 30 to 35 minutes. You’ll know it’s done when the fruit is bubbling around the edges and the topping is deep golden brown and firm to the touch. The aroma of baked peaches and blueberries will fill your kitchen.

Step 7

Remove the crumble from the oven and let it cool on a wire rack for at least 10 minutes. This resting time allows the filling to set so it doesn’t run when served. Serve warm, optionally topped with a scoop of vanilla ice cream, a dollop of Greek yogurt (for extra protein), or a drizzle of heavy cream. The contrast of warm fruit, crispy crumble, and cold topping is irresistible.

For best results

  • For the best texture, use cold butter straight from the fridge. If the butter warms up during mixing, the crumble will spread and become greasy rather than forming distinct clumps. You can even freeze the butter and grate it into the dry ingredients for even distribution. This technique ensures that the butter melts slowly in the oven, creating steam pockets that result in a light, flaky topping.
  • Don't skip the cornstarch. Fresh fruit releases a lot of liquid during baking, and without a thickener, your crumble will be soupy. Cornstarch works best because it thickens at a lower temperature than flour and creates a clear, glossy sauce. If you prefer a gluten-free option, use arrowroot powder or tapioca starch in the same quantity.
  • Choose ripe but firm peaches. Overly soft peaches will break down too much and make the filling mushy. If your peaches are underripe, they'll lack sweetness and be tough. Look for peaches that yield slightly to gentle pressure and have a fragrant aroma. To easily peel peaches, score an 'X' on the bottom, blanch in boiling water for 30 seconds, then plunge into ice water—the skins will slip right off.
  • Make it high-protein: Stir in one scoop (about 30g) of vanilla or unflavored protein powder into the crumble topping. This adds 10-15g of protein per serving without altering the flavor significantly. You can also mix protein powder into the fruit filling, but be aware it may thicken it slightly. For a dairy-free version, use coconut oil or vegan butter in place of regular butter.
  • Storage and reheating: Store leftovers in an airtight container in the refrigerator for up to 4 days. The crumble will soften over time, but you can reheat it in a 350°F oven for 10 minutes to restore some crispness. Alternatively, microwave individual portions for 30-45 seconds. This crumble also freezes well: assemble the unbaked crumble, cover tightly, and freeze for up to 3 months. Bake directly from frozen, adding 10-15 minutes to the baking time.
  • For a more decadent topping, replace half the oats with chopped nuts like pecans or almonds. Nuts add healthy fats and a satisfying crunch. You can also add a pinch of nutmeg or cardamom to the crumble for a flavor twist. If you like a sweeter topping, increase the brown sugar to 1/2 cup, but note that the fruit itself provides natural sweetness.

Variations

  • Vegan & Dairy-Free: Use coconut oil or a plant-based butter stick in place of regular butter. Ensure your oats are certified gluten-free if needed. For the topping, you can also use a mix of almond flour and oats for extra protein. Serve with coconut whipped cream or a drizzle of maple syrup.
  • Gluten-Free: Substitute all-purpose flour with a 1:1 gluten-free baking flour blend or oat flour (make sure oats are certified gluten-free). The texture will be slightly more delicate but still delicious. You can also use almond flour for a nuttier flavor, but reduce the amount to 1/3 cup as almond flour is more absorbent.
  • Berry Medley: Replace the peaches with an equal amount of raspberries, blackberries, or chopped strawberries. A mix of blueberries and raspberries creates a vibrant red-blue filling. Adjust sugar based on tartness; raspberries may require an extra tablespoon of sugar.
  • Stone Fruit Swap: Use nectarines, plums, or apricots instead of peaches. Each fruit brings a unique flavor: nectarines are slightly firmer, plums are tarter, and apricots have a delicate floral note. You can also combine multiple stone fruits for a colorful crumble.
  • Spiced Chai Twist: Add 1 teaspoon of chai spice blend (cinnamon, cardamom, ginger, cloves, nutmeg) to the fruit filling. This warming spice mix pairs beautifully with peaches and blueberries, giving the dessert a cozy autumn feel. Reduce the cinnamon to 1/4 teaspoon to avoid overpowering.

Nutrition

  • Calories215 kcal
  • Total Fat12g
  • Saturated Fat7g
  • Cholesterol45mg
  • Sodium180mg
  • Total Carbohydrates26g
  • Dietary Fiber1g
  • Sugars17g
  • Protein3g

Common Questions

Can I use frozen blueberries and peaches?
Yes, you can use frozen fruit without thawing. In fact, frozen fruit often works well because it holds its shape better during baking. However, frozen fruit releases more liquid, so increase the cornstarch to 1.5 tablespoons to compensate. You may also need to add 5-10 minutes to the baking time. Do not thaw the fruit first, as it will become mushy.
How do I make this crumble lower in sugar?
You can reduce the granulated sugar in the filling to 1 tablespoon and the brown sugar in the topping to 1/4 cup. The fruit’s natural sweetness will still shine. Alternatively, use a zero-calorie sweetener like erythritol or monk fruit sweetener in place of the sugars. Keep in mind that the texture may be slightly different, and the topping might not brown as deeply.
Can I prepare this crumble ahead of time?
Absolutely! You can assemble the entire crumble (fruit filling and topping) in the baking dish, cover it with plastic wrap, and refrigerate for up to 24 hours before baking. When ready to bake, remove the plastic wrap and bake as directed, adding 5-10 minutes since the dish starts cold. You can also freeze the unbaked crumble for up to 3 months; bake from frozen, adding 15-20 minutes.
Why is my crumble topping not crispy?
A soggy topping usually results from either too much moisture in the fruit or the topping being pressed down too firmly. Make sure your fruit is not overly ripe or waterlogged. If using frozen fruit, do not thaw it. Also, ensure your butter is very cold and that you don’t overmix the topping—leave some pea-sized butter chunks. Finally, bake long enough for the topping to turn deep golden brown.
Can I add protein powder to this recipe?
Yes, adding a scoop of vanilla or unflavored protein powder (whey, casein, or plant-based) to the crumble topping is a great way to boost protein. I recommend using a protein powder that blends well, such as a whey isolate or a pea protein isolate. Mix it with the dry ingredients before adding the butter. Note that some protein powders may cause the topping to brown faster, so keep an eye on it during the last 5 minutes of baking.
How should I store leftovers?
Store any leftover crumble in an airtight container in the refrigerator for up to 4 days. The texture will soften, but it’s still delicious cold or reheated. To reheat, place a portion in a microwave-safe dish and microwave for 30-45 seconds, or reheat in a 350°F oven for 10 minutes to crisp up the topping. You can also enjoy it cold straight from the fridge like a fruit parfait.
Can I make this crumble without oats?
Yes, you can substitute the oats with an equal amount of additional flour (all-purpose or almond flour) or with crushed graham crackers for a different texture. Keep in mind that oats provide a hearty, chewy texture and fiber, so without them the topping will be more like a streusel. If using almond flour, reduce the butter to 3 tablespoons as almond flour is high in fat.