This blueberry crumble pie is one of those recipes I come back to every time I need a dessert that genuinely impresses without requiring hours in the kitchen. Two pounds of blueberries get tossed with a touch of citrus and cinnamon, then buried under a thick, buttery crumble made with coconut flour, oats, and sliced almonds.
What I love about this recipe is how forgiving it is. Fresh or frozen blueberries both work beautifully, the crumble topping comes together in a food processor in under a minute, and the whole thing bakes into this bubbling, golden masterpiece that tastes like you spent all day on it.
The coconut flour gives the crumble an almost shortbread-like texture that pairs perfectly with the jammy blueberry filling underneath. Whether you serve it warm with a scoop of vanilla ice cream or let it cool and slice it the next day, every bite delivers that ideal balance of sweet, tart, and buttery crunch.
If you have blueberries in your fridge or freezer right now, this is exactly what you should do with them.
Blueberry Crumble Pie (Coconut Flour Crumb Topping)
Ingredients
Filling Ingredients
- 2 pounds blueberries (6 cups) frozen or fresh
- 5 tablespoons orange or lemon juice fresh
- 2 tablespoons coconut flour
- ¼ cup organic pure cane sugar
- 2 teaspoons ground cinnamon
Crumble Topping Ingredients
- 1 cup coconut flour
- 1 cup organic pure cane sugar
- 1 cup sliced almonds optional
- 1 cup old-fashioned rolled oats
- ½ cup unsalted butter (1 stick) cold and cubed
- butter or non-stick spray for greasing baking dish
Instructions
- Preheat your oven to 350°F / 175°C (160°C fan-forced). Lightly grease a 9×13 inch (23x33cm) baking dish with butter or non-stick spray.
Filling Instructions
- In a large bowl, mix blueberries and orange or lemon juice.
- Next, in a separate bowl, combine together flour, sugar, and cinnamon.
- Add the flour mixture to the blueberries and mix until well combined. Pour into a greased 9×13 inch (23x33cm) baking dish and spread evenly.
Crumble Topping Instructions
- Use a food processor with a steel blade to pulse together sugar, flour, and butter until well combined.
- Transfer the butter-flour-sugar mixture to a separate bowl and toss with the oats and sliced almonds (if using) until evenly combined.
- Spread the crumble topping evenly over the blueberry filling, pressing down very gently. Bake at 350°F / 175°C (160°C fan-forced) for 45-55 minutes, or until the topping is golden brown and the blueberry filling is bubbling around the edges.
- Let the crumble pie cool on a wire rack for at least 20-30 minutes before serving. This allows the filling to thicken and set so slices hold together.
- Top with a scoop of ice cream or whipped cream if desired.
Nutrition
What Makes This Blueberry Crumble Pie Special
Most blueberry crumble recipes use all-purpose flour for both the filling and the topping. This version uses coconut flour instead, which does two important things: it absorbs excess moisture from the blueberries more efficiently, giving you a filling that is jammy rather than soupy, and it creates a topping with an almost shortbread-like crumble texture that shatters beautifully when you break into it with a spoon.
The combination of oats and sliced almonds in the topping adds layers of texture you simply do not get from a traditional flour-only crumble. The oats toast in the oven and become chewy-crisp, while the almonds add a nutty richness that complements the sweet-tart blueberries perfectly.
And then there is the cinnamon. A measured amount of ground cinnamon in the filling adds warmth without overwhelming the bright blueberry flavour — especially when paired with the citrus juice, which lifts everything and prevents the filling from tasting one-dimensionally sweet.
Equipment You’ll Need
- 9×13 inch (23x33cm) baking dish — this size accommodates two pounds of blueberries plus a generous topping layer without overflowing during baking.
- Food processor with steel blade — essential for cutting the cold butter into the coconut flour and sugar. This creates the sandy, clumpy texture that defines a great crumble. A pastry cutter can work in a pinch, but the food processor is faster and more consistent.
- Large mixing bowl — for tossing the blueberries with the citrus juice and dry filling ingredients.
- Medium mixing bowl — for combining the processed butter mixture with the oats and almonds.
- Wire cooling rack — lets air circulate under the hot baking dish so the crumble sets evenly rather than steaming on the countertop and going soggy on the bottom.
Nice to have: parchment paper placed under the baking dish on a sheet pan catches any bubbling juices and saves you cleanup time.
Tips for Best Results
- Keep the butter ice-cold. Cut it into small cubes and return it to the fridge while you prepare the filling. Cold butter creates steam pockets during baking, which is what gives the crumble its flaky, layered texture.
- Do not thaw frozen blueberries. Adding them straight from the freezer prevents them from turning to mush during assembly and ensures they release their juices gradually in the oven.
- Use fresh citrus juice, not bottled. Fresh lemon or orange juice has a brightness that bottled juice simply cannot match. It makes a noticeable difference in the finished filling.
- Do not skip the cooling time. The filling needs at least 20-30 minutes out of the oven to thicken. Cutting in too early means a runny filling that will not hold its shape on the plate.
- Press the crumble gently. A very light press helps the topping adhere to the filling, but packing it down too firmly will result in a dense, bread-like layer instead of a crumbly one.
Substitutions and Variations
- Mixed berries: Replace half the blueberries with raspberries, blackberries, or sliced strawberries for a mixed berry crumble pie.
- Nut-free version: Omit the sliced almonds and add an extra ¼ cup of rolled oats or substitute with unsweetened coconut flakes.
- Regular flour: If you do not have coconut flour, use 1½ cups all-purpose flour for the topping and 3 tablespoons for the filling. Note that coconut flour absorbs significantly more liquid, so the ratios are not 1:1.
- Reduced sugar: Cut the topping sugar to ¾ cup and add 1 tablespoon of honey or maple syrup to the filling for a less sweet but still balanced result.
- Vegan adaptation: Replace the butter with an equal amount of cold coconut oil or vegan butter, cut into cubes, and process the same way.
- Spice variation: Add ¼ teaspoon of freshly grated nutmeg and a pinch of cardamom to the filling alongside the cinnamon for a more complex spice profile.
Storage and Reheating
- Room temperature: Cover loosely with foil and keep at room temperature for up to one day — the crumble topping stays crispiest this way.
- Refrigerator: Cover tightly with plastic wrap or transfer to an airtight container. Keeps well for up to 4 days. The topping will soften slightly.
- Freezer: Wrap individual portions in plastic wrap, then aluminium foil. Freeze for up to 3 months. Thaw overnight in the fridge before reheating.
- Reheating: Place slices on a baking sheet and reheat at 350°F / 175°C for 10-12 minutes until warmed through and the topping crisps back up. Avoid the microwave — it turns the crumble soggy.
What to Serve With This
- Vanilla ice cream — the classic pairing. The cold, creamy ice cream melting into the warm blueberry filling is unbeatable.
- Freshly whipped cream — lightly sweetened with a splash of vanilla extract. Keep it soft and billowy rather than stiffly whipped.
- Greek yoghurt — for a brunch-appropriate serving, a dollop of thick Greek yoghurt balances the sweetness and adds protein.
- Crème anglaise — a pourable vanilla custard turns each serving into something truly elegant for dinner parties.
- On its own with coffee — a slightly cooled slice alongside a strong cup of coffee is one of the best simple pleasures in baking.
Frequently Asked Questions
Can I use a pie crust instead of just a baking dish?
Yes, you can pour the filling into a pre-baked 9-inch pie crust and add the crumble topping on top. Blind bake the crust at 375°F / 190°C for 12-15 minutes before filling to prevent a soggy bottom. This makes it a true crumble-topped pie rather than a crumble baked in a dish.
Why is my blueberry crumble filling watery?
The most common reason is not allowing enough cooling time. The coconut flour and natural pectin in the blueberries need time to absorb the juices and thicken the filling. Always let the crumble rest for at least 20-30 minutes before serving. If you find it consistently runny, add an extra tablespoon of coconut flour to the filling next time.
Can I make this blueberry crumble pie ahead of time?
Absolutely. Prepare the filling and crumble topping separately up to 24 hours in advance. Store both in the fridge in separate airtight containers. When ready to bake, pour the filling into the dish, top with the crumble, and bake as directed — you may need to add 5 extra minutes of baking time since both components will be cold.
Do I need to thaw frozen blueberries first?
No, and it is actually better if you do not. Frozen blueberries hold their shape during assembly and release their juices slowly and evenly during baking. Thawed blueberries turn to mush more easily and can make the filling overly wet before it even goes into the oven.
What size baking dish should I use?
A 9×13 inch (23x33cm) baking dish is ideal for this recipe. It gives the two pounds of blueberries enough room to spread in an even layer with plenty of space for a thick crumble topping. Using a smaller dish risks the filling bubbling over the sides during baking.
Can I use gluten-free oats to make this fully gluten-free?
If you use certified gluten-free oats and verify your coconut flour is processed in a gluten-free facility, this recipe can be made fully gluten-free. Standard oats are often cross-contaminated with wheat during processing, so check the packaging carefully if this matters for your dietary needs.
The History of Fruit Crumbles
The fruit crumble was born out of necessity during World War II in Britain, when strict rationing of butter, flour, and sugar made traditional pie pastry a luxury most households could not afford. Cooks discovered that a simple mixture of fat, flour, and sugar rubbed together and scattered over fruit created a topping that was satisfying, economical, and required far less of each ingredient than a proper pie crust. The crumble quickly became a household staple and never left — even after rationing ended, families preferred the ease and texture of a crumble over the fussiness of rolling pastry.
In America, the crumble evolved alongside its close cousins — the crisp, the cobbler, and the buckle — each with slightly different toppings but the same philosophy of letting seasonal fruit shine under a simple, baked topping. This version, with its coconut flour base and addition of oats and almonds, reflects the modern trend of adapting the classic crumble with alternative flours and added texture, while keeping the spirit of the original: a humble, delicious dessert anyone can make.
If you try this blueberry crumble pie, I would love to hear how it turned out for you — drop a star rating and a comment below to let me know!
