These blueberry blondies are a great summer bake for weekend gatherings. Juicy blueberry jam and a buttery streusel topping create a dessert that sits somewhere between a cookie bar and blueberry coffee cake. You can easily swap other berries if you prefer.
If you love blueberry muffins, you’ll enjoy these blondies. They have the dense, chewy texture of a brownie but with a buttery, vanilla-forward flavor. A layer of homemade blueberry jam brightens each bite, and the streusel adds a tender crunchy finish for a well-balanced dessert.
Prefer other blondie variations? Try chocolate chip brown butter blondies, snickerdoodle bars, or white chocolate blondies for more inspiration.
Ingredients for this Blueberry blondies recipe
Below are the ingredient groups you’ll need. Exact measurements and the full recipe are in the recipe card at the bottom of the page.
Blondie base
- Unsalted butter: softened so it creams easily with the sugars.
- Light brown sugar: provides moisture and a mild caramel note; dark brown can be used for a deeper flavor.
- Granulated sugar: balances sweetness and structure.
- Large egg: binds the batter and gives structure.
- Vanilla extract: enhances the overall flavor.
- All-purpose flour: for best results measure by weight and sift to remove lumps.
- Baking powder and baking soda: small amounts help the blondies rise slightly.
- Salt: balances sweetness and enhances flavors.
Blueberry topping
- Frozen wild blueberries: convenient and flavorful year-round; fresh blueberries work too.
- Cornstarch: thickens the berry mixture into a jammy consistency.
- Water: helps dissolve the cornstarch and loosen the jam.
- Granulated sugar: sweetens the topping.
- Lemon juice and zest: brighten and enhance the blueberry flavor.
Streusel topping
- All-purpose flour: the base for the crumbly streusel.
- Brown sugar and granulated sugar: add sweetness and texture.
- Ground cinnamon: optional, adds warm spice.
- Pinch of salt: balances sweetness.
- Unsalted butter: melted to bind the streusel into crumbs.
How to make this blueberry blondies recipe
Scroll to the recipe card below for the complete ingredient amounts and a printable version. The steps here summarize the process.
- Preheat the oven to 350°F and grease or line an 8×8-inch square pan with parchment paper.
Make the blueberry topping
- Combine blueberries, cornstarch, sugar, lemon juice, lemon zest, and water in a medium saucepan.
- Cook over medium heat, stirring occasionally, until the mixture becomes jammy and slightly thickened. Transfer to a bowl and cool completely.
Make the streusel topping
- In a small bowl mix the flour, granulated sugar, brown sugar, cinnamon, and salt.
- Pour melted butter over the dry ingredients and stir with a fork until crumbs form. Chill the streusel while you prepare the blondie base.
Make the blondie base
- Cream the softened butter with granulated and brown sugar until smooth.
- Beat in the egg and vanilla until fully combined.
- Fold in the flour, cornstarch, baking powder, baking soda, and salt just until a soft dough forms.
- Press the blondie batter evenly into the prepared pan. Spread the cooled blueberry jam over the batter, sprinkle the streusel on top, and bake.
- Bake until the edges are golden and a toothpick in the center comes out clean, about 40 minutes.
- Cool completely before dusting with powdered sugar if desired, then slice into squares.
Why you need to make this recipe!
- Bright blueberry flavor balanced with a buttery blondie base and crunchy streusel.
- Uses simple pantry ingredients and one bowl for the batter, making it easy to prepare.
- Bars are easy to serve and loved by crowds for their fudgy, tender texture.
Frequently Asked Questions – FAQ
How to store leftover blondies?
Store blondies in an airtight container at room temperature for 3–4 days, in the refrigerator for up to a week, or freeze for up to one month. Thaw in the fridge or at room temperature before serving.
Can I use fresh blueberries instead of frozen?
Yes. Frozen wild blueberries are convenient and often more flavorful year-round, but fresh blueberries work well. Wild berries tend to have a more intense flavor than conventional blueberries.
What different flavors can I try with this recipe?
- Add more lemon or a lemon glaze for lemon-blueberry blondies.
- Fold white chocolate chips into the batter for white chocolate blueberry blondies.
- Swap strawberries, blackberries, or raspberries for the topping to change the flavor profile.
Can I make this recipe gluten-free?
Yes. Substitute a 1:1 gluten-free flour blend that contains xanthan gum or a similar binder to maintain the texture.
The Best Blueberry blondies recipe
Blueberry Blondies Recipe
Print Recipe
Ingredients
Blondie Base
- 1/2 cup unsalted butter softened
- 1/2 cup light brown sugar packed
- 1/2 cup granulated sugar
- 1 large egg
- 1 teaspoon vanilla extract
- 1 &1/2 cup all-purpose flour
- 1/2 tablespoon cornstarch
- 1/4 teaspoon baking powder
- 1/8 teaspoon baking soda
- 1/4 teaspoon salt
Blueberry Topping
- 1 cup frozen wild blueberries
- 1 tablespoon cornstarch
- 1 tablespoon water
- 1 & 1/2 tablespoon granulated sugar
- 2 tablespoon lemon juice
- zest of 1 lemon
Streusel Topping
- 1/3 cup all-purpose flour
- 2 tablespoons brown sugar
- 2 tablespoons granulated sugar
- 1/4 teaspoon ground cinnamon
- Pinch of salt
- 3 tablespoons unsalted butter melted
Instructions
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Preheat oven to 350°F and grease or line an 8×8-inch baking pan with parchment paper.
Make the blueberry topping
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In a medium saucepan, combine blueberries, cornstarch, sugar, lemon juice, lemon zest, and water.
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Cook over medium heat, stirring occasionally, until thick and jammy. Remove from heat and cool completely.
Make the Streusel topping
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Mix flour, granulated sugar, brown sugar, cinnamon, and salt in a small bowl.
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Stir in melted butter until crumbly and chill while preparing the blondie base.
Make the blondie base
-
Cream butter with granulated and brown sugar until smooth.
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Add the egg and vanilla and mix until combined.
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Fold in flour, cornstarch, baking powder, baking soda, and salt until just combined.
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Press batter into the pan, spread cooled blueberry jam over it, then sprinkle the streusel on top.
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Bake 40 minutes or until the edges are golden and a toothpick comes out clean.
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Cool completely before slicing; dust with powdered sugar if desired.
Nutrition
Nutrition information is an estimate and should be used as a guideline.
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