This gluten free blueberry crumble is sure to be a hit at your next party or gathering! A layer of buttery and crumbly crust combined with a sweet blueberry filling and topped with a an irresistible crunchy oatmeal topping.

I absolutely love fruit desserts. This blueberry crumble is one of my favorites, along with these no bake blueberry cheesecake parfaits and oven baked oranges! There is something about fruit in desserts that makes for the perfect flavor combination.
The combination of sweet, juicy blueberries along with a buttery, slightly crispy crust makes them so hard to put down. If you love fruit filled desserts, you will fall in love with these crumble bars.
I worked really hard to develop this recipe, and tweaked it multiple times to get it just right. After making numerous pans of blueberry crumble, I was finally able to create the perfect recipe! And now, I can’t stop making it!
If you're looking for more gluten free desserts, check out these almond flour peanut butter cookies or these 3 ingredient oatmeal cookies!
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Reasons This Works
- Every single bite has the perfect balance of fruit, crust and topping in it. The bars are have just enough sweetness, but are not overly sweet.
- These blueberry crumble bars are so flavorful- the buttery crust combined with the sweetness from the blueberries makes for an excellent combination.
- The blueberry crumble bars are great way to use up extra blueberries.
- These can easily be made into low calorie or low sugar bars. See the healthy modifications section in the recipe notes.
Ingredients Needed
Ingredients Notes
Crust:
- Flour: this recipe works with both gluten free flour and all purpose flour. The gluten free flour must be 1:1 baking alternative flour that contains xanthan gum (I love using Bob’s Red Mill brand).
- White Sugar & Brown sugar: adds sweetness to the crust.
- Egg: binds everything together.
- Baking powder & salt: adds flavor and helps the crust rise.
Filling:
- Blueberries: use either fresh or frozen. If using frozen blueberries, thaw fully and drain all juice before using them. (Cooking from frozen will make the blueberry crumble have too much liquid).
- Cinnamon: adds flavor.
- Corn starch: helps to thicken the blueberry filling.
Topping
- Oatmeal: this has been made with old fashioned oatmeal and quick cooking oats. Both will work, however I prefer the old fashioned oatmeal because it creates a chewy topping.
- Brown sugar: adds sweetness. Decrease the amount of brown sugar used if looking for a low sugar option.
- Cinnamon: adds flavor.
How To Buy Good Blueberries
- Blueberries should be plump and round. They should not be damaged or smashed.
- The skin on the blueberries should be smooth; avoid blueberries that are wrinkled or shriveled.
- Blueberries should have a deep blue color. Do not use blueberries that are green in color.
- Shake the container slightly before purchasing. Look for any signs of mold on the berries and avoid if seen.
Step by Step Instructions
Prepare the Crust
Combine all dry ingredients in a medium mixing bowl and mix until combined. Cut the butter into small pieces and add to the flour. Add the beaten egg. Mix using two forks or a pastry cutter. Mix until no large pieces of butter remain and the mixture is very crumbly (It may take 1 -2 minutes to achieve this).
Pro tip: use butter that is room temperature or slightly cold. This will help achieve a crumbly texture in the crust. Do NOT use melted butter!
Press the crust firmly into the bottom of the prepared baking pan. The crust will be crumbly and this is ok!
Make the Filling:
Combine the blueberries, cinnamon, lemon juice and corn starch. I like to add everything into a large zip lock bag, seal it shut, and shake everything around in the bag until it is fully coated.
Once the filling is mixed, place it on top of the crust.
Make the Topping:
Combine the oatmeal, brown sugar and cinnamon. Mix well and sprinkle evenly over the blueberries. Bake and let cool before serving. (Full instructions below!)
Storage Instructions
Store the blueberry crumble in the refrigerator after baking. Let the blueberry bars cool and then cover the pan tightly with foil to prevent any air from getting in. For best quality, consume within 3 days of baking.
The crumble bars can be frozen for up to 3 months. The quality and texture of the blueberry bars will be slightly affected if it is frozen. Thaw the bars at room temperature prior to serving.
Expert Tips
- Purchase blueberries when they are in season (typically the summer months). This will result in a juicy and sweeter berry.
- The crust will be very crumbly prior to baking it. Make sure the press it down firmly in the pan. The crust will solidify once it is cooked.
- Make an extra-large batch by doubling all ingredients and baking in a 9x13 inch pan.
Frequently Asked Questions
This recipe can be made with fresh or frozen blueberries. Fresh blueberries are best during the summer months, because they are usually juicy and sweet!
If using frozen blueberries, defrost the blueberries entirely before baking them. Drain all of the juice after defrosting them.
These will last 3-4 days in the refrigerator and up to 3 months in the freezer.
Nutrition Information
Here are the nutrition facts for 1 serving of crumble:
- 235 calories
- 3 grams of protein
- 9 grams of fat
- 37 grams of carbohydrate
Blueberries Nutrition Information
Blueberries may be small in size, but they are high in nutrition. In fact, they are considered a very nutrient dense food source.
Blueberries are an excellent source of fiber. 1 cup of blueberries contains 3.6 grams of fiber. Fiber plays a role in keeping you full for a long period of time and aiding in digestion.
Blueberries also contain 24% of your DV of Vitamin C.
Blueberries are rich in anthocyanin. Research has found that moderate intake of anthocyanin may reduce your risk of cardiovascular disease (source).
Research has also found that blueberries may have positive effects on inflammation and delaying the effects of Alzheimer’s disease. More information on blueberries can be found here.
Healthy Modifications
Looking to make some healthy blueberry crumble bars? Here’s a couple modifications that can be made to either reduce the calorie, fat or sugar content:
- Leave off the crust: Simply grease your pan, then add the blueberry filling and topping. Bake in the oven for 20 minutes. Plates and spoons will be required when eating this version!
- Leave off the topping: reduce the sugar and carbs by leaving off the topping or cutting the amount of ingredients used in half. The blueberry bars will still taste good!
- Decrease the amount of sugar: use ¼ cup of sugar for the topping. Continue to use the same amount of oatmeal and cinnamon.
- Make a thinner crust: cut the ingredients for the crust in half, however continue with the normal amounts for the filling and topping. This will result in a very thin crust, however it will lower the calories and fat.
- Split it half and half: have a split family where half prefer the low calorie and the other half want the regular version? No problem! Sprinkle the topping on only half of the blueberry crumble bars. Another alternative is to add crust to only half of the bars, and leave the other side without crust.
More Delicious Desserts
Gluten Free Blueberry Crumble
Ingredients
Crust
- 1.5 cup gluten free flour
- 1 teaspoon baking powder
- ¼ teaspoon salt
- 2 tablespoons brown sugar
- ¼ c granulated white sugar
- 1 large egg beaten
- ½ cup butter room temperature, cannot be melted
Filling
- 3.5 cups blueberries washed and stems removed
- 1 teaspoon cinnamon
- 2 teaspoon cornstarch
- ½ teaspoon lemon juice
Topping
- ½ cup old fashioned oatmeal gluten free if desired
- ½ cup brown sugar
- 1 teaspoon cinnamon
Instructions
Crust:
- In a medium mixing bowl, combine the flour, baking powder, salt, brown sugar and white sugar. Mix until combined.
- Cut the butter into small pieces and add to mixture. Add the beaten egg. (Note: the butter should be at room temperature. It should NOT be melted).
- Mix until combined using a pastry cutter or 2 forks. The mixture should be very crumbly with no large pieces of butter remaining.
- Press the crust into the bottom of an 8x8 inch pan. Use your hands to press the crust down firmly into the pan. (Note: the crust will appear very crumbly, this is ok! It solidifies when cooked).
Filling:
- Combine the blueberries, cinnamon, cornstarch and lemon juice in a large mixing bowl. Mix until blueberries are evenly coated.
- Pour the blueberries evenly over the prepared crust.
Topping:
- In a small mixing bowl, combine the oatmeal, brown sugar and cinnamon. Mix well.
- Sprinkle evenly over the blueberries.
- Bake the blueberry bars for 35-40 minutes. Let cool and serve!
Maggie
Yummy- I love blueberries and oatmeal together. This looks awesome! Thank you!
Marilyn Dispensa
You didn't put the bake temperature in the recipe or i missed it.
Pinch of Wellness
Bake at 350!
Marilyn Dispensa
Thanks. I took a guess and picked 350. I made a bunch of modifications. for flour i used 1/2 cup pecan, 1/2 cup almond, 1/2 cup coconut flour. I made too much of the buttom crust so i took that and added the oats and a little more brown sugar. We'll see how it turned out.
Ashwandi
I made these last night and they were excellent!
Ashlee Welter
The best!!