Blueberry Crumble Bars
Blueberries are abundant right now, and I just couldn’t resist adding them into a sweet treat. With a layer of gluten-free almondy crust, jammy blueberry filling, and delicious crumble to top them off, Blueberry Crumble Bars have been my recent sweet treat obsession. I’ve made several batches over the past couple of weeks and keep a bag of bars stocked in my freezer for when emergency strikes!
Table of Contents
- Blueberry Crumble Bar Ingredients
- Step 1—Make the Crust
- Step 2—Prepare the Blueberry Filling
- Step 3—Sprinkle On the Crumble Topping
- Step 4—Bake the Blueberry Crumble Bars
- Step 5—Cool, Slice, and Serve!
- More Delicious Desserts
Blueberry Crumble Bar Ingredients
To make Blueberry Crumble Bars, you will need the following ingredients:
Crust and Crumble Ingredients
- 1 cup (120 grams) almond flour
- 1½ cups (260 grams) gluten-free all-purpose flour (I like this one)
- 1/8 teaspoon sea salt
- 1/2 cup (90 grams) light brown sugar
- 3/4 cup (146 grams) melted butter
- 1/2 teaspoon vanilla extract
- 1/4 teaspoon almond extract
- Zest of half a lemon
Blueberry Filling Ingredients
- 1/4 cup (50 grams) white sugar
- Zest of half a lemon
- 4 cups (545 grams) fresh blueberries
- 1 tablespoon cornstarch
- 1/2 teaspoon vanilla extract
- Pinch of sea salt
Step 1—Make the Crust
Before we dive into making the crust, you need to preheat your oven to 350°F. Grease and line an 8×8 inch baking pan with parchment paper, then set that aside while you prepare the crust.
The crust in this recipe doubles as the crumbly topping for the Blueberry Crumble Bars. The best way to describe the texture is sugar cookie meets pastry crust, so a little bit softer than a traditional pastry crust.
To make the crust, sift together the almond flour, all-purpose gluten-free flour, and sea salt in a large mixing bowl. Whisk to combine.
Add the light brown sugar, melted butter, vanilla, almond extract, and lemon zest. Use your fingers to mix everything together. The final result will be a clumpy, slightly sandy mixture. Set aside 1½ cups to use for the topping.
Transfer 3 cups of the crust mixture to the prepared 8×8 inch pan. Use your fingers to spread the crust into an even layer across the bottom of the pan. I like to use the bottom of a measuring cup to pack down, smooth out, and level the crust. Set aside while you prepare the filling.
Step 2—Prepare the Blueberry Filling
In a medium mixing bowl, use your fingers to massage the lemon zest into the white sugar. This helps release those delicious citrusy oils in the zest and infuse the sugar.
Measure in the blueberries and cornstarch. Fold together with a baking spatula until the blueberries are coated in the lemon sugar and cornstarch. Add the vanilla extract and sea salt, then fold again to distribute.
Pour the blueberry filling over the crust, using a baking spatula to spread the filling out evenly.
Step 3—Sprinkle On the Crumble Topping
Sprinkle the reserved 1½ cups of the crust mixture over top of the blueberry filling. The topping should mostly cover the blueberries. It’s ok if bits of blue are still visible.
Step 4—Bake the Blueberry Crumble Bars
Bake the Blueberry Crumble Bars in the preheated oven for 70 minutes, or until the top is golden brown and the blueberry filling is bubbling up around the edges and between the crumble topping. Keep an eye on the bars as they bake because every oven is a bit different, so baking time may vary slightly.
Step 5—Cool, Slice, and Serve!
Once the Blueberry Crumble Bars are out of the oven, allow the bars to cool completely in their pan at room temperature. Once completely cooled, transfer to the fridge for half an hour. This quick chilling makes the bars easier to slice.
Remove the chilled bars from their pan by gently tugging on the parchment lining. Using a sharp knife, slice into nine approximately even bars. You can slice the bars smaller if that is your preference—I’ve had success slicing 12 roughly even-sized bars.
Store the bars in an airtight container in the fridge for up to four days. The crust and crumble will soften slightly as the bars age. These Blueberry Crumble Bars also freeze very nicely. I like to freeze them in a single layer on a lined sheet pan, then transfer the frozen bars to a Stasher Bag to store.
More Delicious Dessert Recipes
If you loved this Blueberry Crumble Bar recipe, be sure to try these other delicious desserts:
Lemon Pistachio Loaf with Lemon Glaze
White Chocolate and Pistachio Cookies with Cranberries
If you make it, please tag me on Pinterest or Instagram so I can see! I love to see what you all are making.
Feel free to leave any questions, comments, or reviews below. I love to hear from you!
Blueberry Crumble Bars
Equipment
- 8x8 inch square baking pan
- Parchment paper
Ingredients
For the Crust and Crumble
- 1 cup almond flour (120 grams)
- 1½ cups gluten-free all-purpose flour* (260 grams)
- 1/8 teaspoon sea salt
- 1/2 cup light brown sugar (90 grams)
- 3/4 cup melted butter (146 grams)
- 1/2 teaspoon pure vanilla extract
- 1/4 teaspoon almond extract
- Zest of half a lemon
For the Blueberry Filling
- 1/4 cup white sugar (50 grams)
- Zest of half a lemon
- 4 cups fresh blueberries (545 grams)
- 1 tablespoon cornstarch
- 1/2 teaspoon pure vanilla extract
- pinch of sea salt
Instructions
- Preheat the oven to 350℉. Grease and line an 8x8 inch baking pan with parchment paper. Set aside.
Make the Crust
- In a large mixing bowl, sift together the almond flour, all-purpose gluten-free flour, and sea salt. Whisk to combine.
- Add the light brown sugar, melted butter, vanilla, almond extract, and lemon zest. Use your fingers to mix everything together. The final result will be a clumpy, slightly sandy mixture. Set aside 1½ cups to use for the topping.
- Transfer 3 cups of the crust mixture to the prepared 8x8 inch pan. Use your fingers to spread the crust into an even layer across the bottom of the pan. I like to use the bottom of a measuring cup to pack down, smooth out, and level the crust. Set aside while you prepare the filling.
Prepare the Blueberry Filling
- In a medium mixing bowl, use your fingers to massage the lemon zest into the white sugar. This helps release those delicious citrusy oils in the lemon zest and infuse the sugar.
- Measure in the blueberries and cornstarch. Fold together with a baking spatula until the blueberries are coated in the lemon sugar and cornstarch. Add the vanilla extract and sea salt, then fold again to distribute.
- Pour the blueberry filling over the crust, using a baking spatula to spread the filling out evenly.
Assemble, Bake, and Set
- Sprinkle the reserved 1½ cups of the crust mixture over top of the blueberry filling. The topping should mostly cover the blueberries. It's ok if bits of blue are still visible.
- Bake the blueberry crumble bars in the preheated oven for 70 minutes, or until the top is golden brown and the blueberry filling is bubbling up around the edges and between the crumble topping.
- Allow the blueberry crumble bars to cool completely in their pan at room temperature. Once completely cooled, transfer to the fridge for half an hour. This quick chilling makes the bars easier to slice.
- Remove the chilled bars from the pan and slice into nine roughly even bars. Store in an airtight container in the fridge for up to four days. The crust and crumble will soften slightly as the bars age.
