A simple summer dessert, these blueberry blondies feature chewy blondie batter layered with blueberry jam and a buttery crumb topping that tastes like blueberry crumble!
Blueberry blondies were a classic bakery treat when I worked as a pastry chef. Instead of fresh blueberries, my version is layered with blueberry jam, similar to blueberry crumb cake, so they’re packed with tons of blueberry flavor!
They have the same fudgy and chewy texture as brownies but without chocolate, making them the perfect easy recipe for any summer-inspired occasion.
Table of Contents
What are Blueberry Blondies?
- Fruity brownie-like bars: They are similar to brownies but are made without chocolate!
- Easy to make: You only need a few staple pantry ingredients, and no mixer is required!
- Packed with blueberry flavor: Just like wild blueberry scones, they are loaded with juicy blueberries!
- Perfect for any occasion: Enjoy them year-round with frozen or fresh blueberries!
Ingredient Notes and Substitutions
Wild Maine blueberries: I used these berries almost exclusively when working as a pastry chef- like making bakery-style blueberry muffins and blueberry rolls! They are preferred because they are packed with more flavor and can be used year-round. Substitute them with fresh blueberries or regular frozen blueberries (note that the jam will have a less intense blueberry flavor).
Brown sugar: This gives the blondie batter a chewy texture and caramelized flavor. Use either light brown sugar or dark brown sugar.
Cornstarch: This ingredient is needed to create a super-thick jam that doesn’t ooze out after baking. Do not substitute it or leave it out, or the blueberry jam will be too thin!
Eggs: You will need one whole egg and one extra egg yolk. The extra egg yolk gives the blondie batter extra fat, which is needed for a fudgy texture. I use this in my strawberry blondies, too!
Full ingredient measurements and instructions can be found in the recipe card below!
Fruity Variations
Feel free to substitute the blueberries for strawberries, raspberries, blackberries, or a combination!
Depending on the berry you use, you may need to use more or less cornstarch to reach a thick jam consistency.
Recipe Instructions
Step 1: Make the blueberry jam. In a small pot, cook the frozen wild blueberries, granulated sugar, lemon juice, and lemon zest until the jam has bright juices and is bubbling. Stir in the cornstarch slurry and cook until thickened. Set aside. (Image 1 below)
Step 2: Make the crumb topping. Combine the all-purpose flour, granulated sugar, brown sugar, and melted butter until crumbs form. Chill in the fridge until ready to use. (Image 2 below)
Step 3: Whisk together the wet ingredients. In a large mixing bowl, whisk together the brown sugar, granulated sugar, egg, egg yolk, and vanilla extract for 1 minute until light and fluffy. (Image 3 below)
Step 4: Stream in the melted butter. Stream the hot melted butter into the bowl, whisking constantly until fully combined. (Image 4 above)
Step 5: Fold in the dry ingredients. Fold in the all-purpose flour, baking powder, and salt until combined. (Image 5 below)
Step 6: Spread the batter into the pan. Evenly spread the blondie batter into the prepared baking pan. (Image 6 below)
Step 7: Layer the blueberry jam. Use an offset spatula to spread the jam evenly on top of the batter. (Image 7 above)
Step 8: Bake the blondies. Sprinkle the crumb topping and extra blueberries on top of the jam. Then bake them until the edges are golden brown. (Image 8 above) Let the pan cool completely on a wire rack before slicing it with a sharp knife.
If you’re as obsessed with berry-stuffed bars as I am, you’ve got to try my jammy mixed berry crumb bars next. They’re the kind of treat that disappears from the pan way too fast, especially if you’re a crumble topping fanatic like me!
If you tried this or any other recipe on my website, please let me know how it went in the comments; I love hearing from you! Also, please leave a star rating while you’re there! You can also tag me on Instagram or Facebook so I can check it out!
Blueberry Blondies
Equipment
Ingredients
Blueberry Jam Filling
- 1 cup frozen wild Maine blueberries, see notes for substitutes
- 2 tablespoons granulated sugar
- 1 teaspoon lemon juice
- 1/4 teaspoon lemon zest
- 2 teaspoons water
- 2 teaspoons corn starch
Crumble
- 1/4 cup all-purpose flour, *See notes below for measuring*
- 1 tablespoon granulated sugar
- 1 tablespoon light brown sugar, packed
- 2 tablespoons unsalted butter, melted
Blondie Batter
- 2/3 cup light brown sugar, packed
- 1/4 cup granulated sugar
- 1 large whole egg
- 1 large egg yolk
- 1 teaspoon vanilla extract
- 1/2 cup unsalted butter, melted
- 1 cup + 2 tablespoons all-purpose flour, *See notes below for measuring*
- 1/2 teaspoons fine sea salt
- 1/4 teaspoon baking powder
- 1/4 cup frozen wild Maine blueberries, for topping
Instructions
- Line a metal square 8×8 baking pan with parchment paper and preheat the oven to 350 F/180 C.
- Cook the frozen blueberries, lemon zest, lemon juice, and sugar over medium heat for 8-9 minutes or until the berries start to release their juices and boil. Whisk together the cornstarch and water and stir it into the jam. Cook for 2 minutes longer until the jam is super thick. Transfer it to a bowl and set it aside to cool completely.1 cup (125 g) frozen wild Maine blueberries, 2 tablespoons (30 g) granulated sugar, 1 teaspoon lemon juice, 1/4 teaspoon lemon zest, 2 teaspoons water, 2 teaspoons corn starch
- In a medium bowl, combine the flour, sugar, brown sugar, and melted butter until crumbs form. Chill in the fridge until ready to use. Before using, break up the crumb into small pieces!1/4 cup (35 g) all-purpose flour, 1 tablespoon (15 g) granulated sugar, 1 tablespoon (15 g) light brown sugar, 2 tablespoons (28 g) unsalted butter
- In a large bowl, whisk together the brown sugar, granulated sugar, egg, egg yolk, and vanilla extract until light and fluffy, about 1 minute. Then whisk in the melted butter. Once combined, fold in the flour, baking powder, and salt.2/3 cup (126 g) light brown sugar, 1/4 cup (50 g) granulated sugar, 1 (55 g) large whole egg, 1 (17 g) large egg yolk, 1 teaspoon vanilla extract, 1/2 cup (113 g) unsalted butter, 1 cup + 2 tablespoons (142 g) all-purpose flour, 1/2 teaspoons fine sea salt, 1/4 teaspoon baking powder
- Evenly spread the batter into the prepared pan.
- Evenly spread the cooled blueberry jam over the top of the batter. Then sprinkle the crumb topping and extra blueberries over the top.1/4 cup (34 g) frozen wild Maine blueberries
- Bake for 28-30 minutes, or until the middle is puffy, the edges are golden brown, and a toothpick inserted into the center comes out covered with just a few moist crumbs.
- Let the pan cool completely on a wire rack. Then lift the parchment paper up to remove it from the pan. Use a sharp knife to cut it into 16 small bars or 9 large bars. Enjoy!
Notes
Tried this recipe?Leave a comment below & tag @cambreabakes on social!
How long would u bake a double batch in 9×13
Hi Amber, it will likely be a similar bake time! I would check them at the indicated bake time and bake a few minutes longer if needed.
I have made this multiple times gluten and dairy free with various fruit. Rhubarb has to be a favorite! I used Bob’s Red Mill 1-1 flour, and Violife plant based butter. Turns out delightful every time.
Yum!! Love that you’re trying it with different fruits. Thanks so much for the kind review Halle! 🙂