These delicious vegan and gluten-free blueberry crumble bars are easy to make with just a few ingredients for the perfect summer dessert!

Stack of 3 blueberry crumble bars on a small plate.

Introduction

Made with fresh, juicy blueberries and a crumbly oat topping, these bars are the perfect balance of sweet and tart.

You’ll need just 8 simple ingredients so they’re a breeze to whip up and though they’re naturally sweetened, vegan and gluten-free, they’re so yummy you’d never guess it!

They can even be served warm with a scoop of vanilla ice cream to an extra delicious treat. Bring them along to your next get-together, BBQ or picnic and they’re sure to be a bit!

Let’s go over what ingredients you’ll need, substitutions, how to make them, as well as tips and tricks for success.

When you’re ready to make them, scroll to the end to find the complete recipe card.

And if you love crisps and crumbles, consider making these apple crumble bars, strawberry oatmeal bars, strawberry rhubarb crisp and apple cranberry crisp next!

Ingredient Notes

Visual of ingredients needed for making a vegan blueberry crumble bar recipe.

The complete list of ingredients with measurements can be found in the recipe card at the end of the post.

  • Almond Flour: Fine almond flour works best but you can make almond meal at home if you don’t have almond flour available. Use a blender or food processor to blend blanched almonds as fine as you can until you have 3/4 cup or 100 g of flour. If you have extra almond flour, you can use it in these zucchini brownies, oatmeal cookies or peanut butter cookies.
  • Oat Flour: Use store-bought or blend your own by processing rolled oats in a food processor or blender, getting it as fine as you can. If you make extra oat flour, you can use it in these oat flour brownies, pancakes or avocado brownies.
  • Rolled oats: Rolled oats, large flake oats or old-fashioned oats work.
  • Butter or Oil: Use melted vegan butter such as Earth Balance, or melted coconut oil. If you purchase plant-based butter, you can also use it in these oatmeal cookie bars, coconut oatmeal cookies or pecan snowball cookies.
  • Maple Syrup: If needed, this can be substituted with agave syrup.
  • Blueberries: Use fresh blueberries, raspberries, black berries, cherries or any mixture of berries.
  • Cornstarch: Needed to thicken the filling. Arrowroot powder also works.

Step-by-Step Instructions

Before You Start: Spray an 8 or 9 inch square baking dish with a light coating of non-stick cooking spray or line with parchment paper and set aside. Preheat the oven to 350 F.

While it’s not required to use parchment paper, it makes it easier to remove the bras from the pan.

If you’re not using parchment paper, just be sure to give the pan a light greasing with non-stick cooking spray or oil.

Step 1: Combine Flours

Combine the almond flour and oat flour in a large bowl and mix well.

Oat flour and almond flour mixed together in a mixing bowl with a spoon in it.

Step 2: Add Wet Ingredients

Add the butter, maple syrup and vanilla and stir well to combine into a uniform batter.

Raw batter in a glass mixing bowl with a wooden spoon.

Step 3: Add Oats

Add the oats and mix well to combine.

Raw batter with oats in it in a glass mixing bowl with a wooden spoon.

Step 4: Mix Blueberries with Cornstarch

In a separate bowl, gently mix the blueberries, sugar (if using) and cornstarch until all the blueberries are coated.

Blueberries coated in cornstarch in a bowl.

Step 5: Assemble Bars & Bake

Add 1/2 of the crumble mixture to the baking dish, firmly pressing it down.

Raw oatmeal bar batter pressed into a baking pan.

Top with the blueberries then add the rest of the crumble on top.

Blueberry crumble oat bars in a baking pan.

Once they’ve cooled, lift from the pan, slice and enjoy!

Bake the bars for 35-40 minutes until the top is golden brown and let cool completely in the pan before slicing. Don’t skip the cooling as it’s needed for the bars to hold together properly.

Recipe FAQs

Can I use a different type of fruit instead of blueberries?

Yes. You can use any fresh berry or chopped stone fruit in this recipe.

Can I make this recipe in advance?

For sure. This is a great make-ahead dessert. Bake the crumble bars then let them cool. Cover well in the pan and store at room temperature for up to 3 days or in the fridge for up to 1 week.

Can I substitute the almond flour with another type of flour?

I have not tested this particular oat crumble recipe with other flours but you can easily pair the blueberry filling with one of these instead:

crumble made with all-purpose flour
crumble made with whole wheat flour
crumble made with gluten-free flour

A blueberry crumble oat bar on a piece of parchment paper.

How to Store

  • Let cool completely before slicing and storing. This is important so they firm up properly.
  • Room Temperature: Store in an airtight container for 3 days.
  • Fridge: Store in a sealed container for up to 1 week.
  • Freezer: Can be frozen but the texture will change. Freeze in a sealed container or freezer-safe bag for up to 3 months. Thaw at room temperature or in the fridge before enjoying cold or warmed in the oven.

Did you try this recipe? I’d love to hear about it! Scroll down to the comment section to leave a star rating and review.
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Stack of 3 blueberry crumble bars on a small plate.

Blueberry Crumble Bars

5 Stars 4 Stars 3 Stars 2 Stars 1 Star 5 from 6 reviews
  • Author: Deryn
  • Prep Time: 15 mins
  • Cook Time: 35 mins
  • Total Time: 50 minutes
  • Yield: 12
  • Category: Dessert
  • Cuisine: American
  • Diet: Vegan
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Description

Delicious, sweet and tart blueberry crumble bars that are completely gluten-free and dairy-free. These lovely bars make the perfect summer dessert when fresh berries are in season. Feel free to switch it up and try fresh raspberries or blackberries instead of blueberries.


Ingredients

For the Crumble

For the Filling

  • 3 cups fresh blueberries (450 g)
  • 1 tbsp cornstarch (7.5 g)
  • 2 tbsp brown sugar or maple syrup (30 g, optional for added sweetness) 

Instructions

  1. Preheat the oven to 350 F (170 C). Spray a 9×9-inch baking dish with a light coating of non-stick cooking spray and set aside.
  2. Combine the almond flour and oat flour in a large mixing bowl and mix well. Add in the vegan butter, maple syrup and vanilla extract and mix well into a uniform batter.
  3. Add in the oats and mix again to distribute throughout.
  4. In a separate bowl, mix together cornstarch, blueberries and sugar, if using. Toss to evenly coat the blueberries.
  5. Press 1/2 of the crust mixture evenly and firmly into the prepared baking dish.
  6. Spread coated blueberries evenly over crust in the baking dish.
  7. Sprinkle the remaining oat mixture over the blueberries.
  8. Bake for 35-40 minutes to bake or until the top is golden brown..
  9. After they bake, let them cool completely before slicing into squares.

Notes

You can swap for any other fresh berries or use a mixture of berries.

Make sure to let the bars cool completely before slicing into squares.

Make your own oat flour by blending 150 g rolled oats in a food processor or blender until they resemble a fine flour consistency.

Store at room temperature for 3 days in a sealed container, in the fridge for up to 1 week or freezer in a sealed container or freezer-safe bag for up to 3 months.


Nutrition

  • Serving Size: 1 bar
  • Calories: 153
  • Sodium: 112 mg
  • Fat: 8 g
  • Carbohydrates: 12 g
  • Fiber: 2 g
  • Protein: 3 g