Classic blueberry blondies get a twist into this blueberry crumble blondie! The perfectly chewy and fudgy batter is swirled with fresh blueberry jam and topped with a buttery crumb to taste just like blueberry crumble!
These blueberry blondies are seriously the best ever. If you are unfamiliar with a blondie, it essentially is a "blonde" brownie, meaning it has the same fudgy and chewy texture as a brownie but doesn't use any chocolate.
I decided to use my strawberry lemon blondie recipe as the base for these blueberry blondies and they turned out PERFECT!
They are so easy to make and you don't even need a mixer to make them.
For more blueberry recipes, try Blueberry Crumb Cake, Blueberry Macarons, and Blueberry Strawberry Shortcake.
Jump to:
why these blueberry blondies work
- These bars are so easy to make and require mostly staple pantry ingredients.
- They taste just like blueberry crumble, but in brownie bar form!
- They are a perfect summer-time treat but can be enjoyed year-round because they use frozen berries.
- Serve them as a breakfast pastry or dessert for any occasion!
ingredient notes
Full ingredient measurements and instructions can be found in the recipe card below!
- Frozen wild blueberries: These blueberries are tiny and have so much more flavor than regular-sized or fresh blueberries!
- Brown sugar: Light brown sugar is preferred but can be substituted with dark brown sugar too.
- Corn starch: This is used to thicken the jam.
recipe instructions
Step 1: Combine the frozen wild blueberries, sugar, lemon juice, and lemon zest in a small pot. Cook over medium heat for 8-9 minutes or until the blueberries have released their bright juices and are bubbling.
Whisk together the water and corn starch, then pour it into the pot and cook for 1 minute longer. The jam should be super thick. Transfer it to a bowl to cool completely.
Step 2: Make the crumb by combining the melted butter, flour, granulated sugar, and brown sugar. It will mostly be one large lump of dough. Place the bowl in the freezer until ready to use, then use your hands to break the crumb up into smaller pieces.
Step 3: Whisk together the egg, egg yolk, vanilla, sugar, and brown sugar for 1 minute or until light and fluffy. Stream the melted butter into the bowl until combined. Finally, fold the flour, baking powder, and salt.
Step 4: Evenly spread the blondie batter into a parchment-lined square 8x8 baking pan. Spoon dollops of the cooled jam over the top of the batter, then use an offset spatula to evenly spread it around the top. It will mix in with some of the batter which is perfect!
Step 5: Sprinkle the crumb pieces and the extra blueberries on top, then bake them at 350 F/180 C for 28-30 minutes, or until the middle looks puffed up and the edges are golden brown. You can also insert a toothpick into the center and it should come out covered in moist crumbs.
expert baking tips
- Use a kitchen scale: Baking with a scale is faster, easier, and overall much more accurate than cup measurements.
- Use room temperature ingredients: Using room temperature ingredients creates a smooth, fully blended batter that will result in a uniform texture and even baking.
- Dark vs. light baking trays: Baking pans conduct heat differently depending on what color it is. If your pan is dark or black you should decrease the heat to 325 F/163 C.
- Cooking times may vary: All ovens are different, and your bars may bake quicker or take longer than the indicated baking time. I recommend always checking on them occasionally and testing for doneness!
faq's
Once cool, you can store the blondies in a bag or sealed container for 3-4 days at room temperature.
Yes! Once cool, cut the blondies and then store them in a sealed container or bag for up to 1 month.
I recommend making the jam and crumbs ahead of time and keeping them in the fridge until ready to use. Once ready, make the blondie batter, and then bake them!
Do I have to use frozen blueberries or can I use fresh ones?
This recipe does best with frozen small wild blueberries. Fresh blueberries will take longer to cook down and the flavor overall isn't as strong!
You definitely could! I think raspberries, strawberries, or blackberries would be SO delicious!
more recipes you'll love
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Recipe 📖
Blueberry Crumble Blondies
Equipment
Ingredients
Blueberry Jam Filling
- 1 cup frozen small wild blueberries
- ¼ teaspoon lemon zest
- 1 teaspoon lemon juice
- 2 tablespoon granulated sugar
- 2 teaspoon corn starch
- 2 teaspoon water
Crumble
- ¼ cup all-purpose flour
- 1 tablespoon granulated sugar
- 1 tablespoon light brown sugar packed
- 2 tablespoon unsalted butter melted
Blondie Batter
- 1 large egg
- 1 large egg yolk
- ⅔ cup light brown sugar packed
- ¼ cup granulated sugar
- 1 teaspoon vanilla extract
- ½ cup unsalted butter melted
- 1 cup + 2 tbsp all-purpose flour
- ¼ teaspoon baking powder
- ½ teaspoon salt
- ¼ cup frozen small wild blueberries for the top
Instructions
- Line a square 8x8 baking pan with parchment paper and preheat the oven to 350 F/180 C.
Make the Jam
- Combine the frozen blueberries, lemon zest, lemon juice, and sugar in a small pot. Cook over medium heat for 8-9 minutes or until the berries start to release their juices and boil.1 cup frozen small wild blueberries, ¼ teaspoon lemon zest, 1 teaspoon lemon juice, 2 tablespoon granulated sugar
- Whisk together the cornstarch and water.2 teaspoon corn starch, 2 teaspoon water
- Pour the cornstarch slurry into the jam and cook for 1-2 minutes longer until the jam is super thick. Then transfer it to a bowl and set it aside to cool completely.
Make the Crumb
- In a small bowl, combine the flour, sugar, brown sugar, and melted butter. Place the bowl in the freezer to chill the crumb while you make the blondie batter. Before using, use your hands to break up the crumb into small peices.¼ cup all-purpose flour, 1 tablespoon granulated sugar, 1 tablespoon light brown sugar, 2 tablespoon unsalted butter
Make the Batter
- In a medium bowl, whisk together the egg, egg yolk, vanilla, brown sugar and sugar until light and pale in color.1 large egg, 1 large egg yolk, ⅔ cup light brown sugar, ¼ cup granulated sugar, 1 teaspoon vanilla extract
- Whisk in the melted butter.½ cup unsalted butter
- Fold in the flour, baking powder, and salt until just combined.1 cup + 2 tablespoon all-purpose flour, ¼ teaspoon baking powder, ½ teaspoon salt
- Evenly spread the batter into the prepared pan.
- Dollop the cooled blueberry jam on top of the batter and use a spatula to evenly spread it over the top. The jam will mix some with the batter which is okay!
- Sprinkle the crumb and the frozen blueberries on top.¼ cup frozen small wild 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 with just a few moist crumbs.
- Let cool completely before cutting then enjoy!
Notes
- Use a kitchen scale: Baking with a scale is faster, easier, and overall much more accurate than cup measurements.
- Use room temperature ingredients: Using room temperature ingredients creates a smooth, fully blended batter that will result in a uniform texture and even baking.
- Dark vs. light baking trays: Baking pans conduct heat differently depending on what color it is. If your pan is dark or black you should decrease the heat to 325 F/163 C.
- Cooking times may vary: All ovens are different, and your bars may bake quicker or take longer than the indicated baking time. I recommend always checking on them occasionally and testing for doneness!
- Can I use regular frozen blueberries or fresh blueberries? This recipe does best with the frozen small wild blueberries. Fresh blueberries will take longer to cook down and the flavor overall isn't as strong!
- Storage: Once cool, store the cut bars in a bag or sealed container at room temperature for 3-4 days.
- Freezing: Store the cut bars in a sealed container or freezer bag for up to 1 month!
The calorie information provided for the recipe is an estimate. The accuracy of the calories listed is not guaranteed.
Andrea says
Oh my deliciousness! Is it okay if I eat them for breakfast? They are made with blueberries so I will be having them for breakfast, snack and dessert. Yummy!
Cambrea Gordon says
I definitely ate more than one for breakfast 😉 Enjoy Andrea!
Patty at Spoonabilities says
Everything about these blueberry blondies are to die for. I love the pairing with the lemony flavor. These are so good!
justin says
Went blueberry picking and froze some, used to bake these and the girls thought they were amazing. Fun weekend treat.
Cambrea Gordon says
What a fun day! Thanks so much for the kind review Justin!
Tara says
Such a fantastic twist on blondies! The color is gorgeous with the use of the blueberries and that texture looks incredible.
Michelle says
Made these last night and they were a hit with my boys! Loved that every bite had blueberries.. yum!
Cambrea Gordon says
Thanks Michelle! I'm happy to hear they were a hit!
Kamna says
These are incredible! Soft, fudgy blondies that are perfectly sweet, with a delicious jammy blueberry topping- huge hit in my house even with people who don't actually like blueberries! Made these once and they're already a fav ❤️
Cambrea Gordon says
Thank you so much Kamna! 🙂
Colleen says
I made a gluten free/dairy free version of these and they turned out fantastic! I used King Arthur Measure for Measure Gluten Free flour (be sure to spoon the flour into the measuring cup and level off, don’t scoop with the measuring cup!) and Earth Balance vegan butter. I brought them to a Father’s Day gathering and everyone loved them! I will definitely make these again!
Cambrea Gordon says
This is amazing!!! Thanks so much for sharing how you made them gluten and dairy free Colleen! I'm so glad everyone loved them!
Tyler says
I can't stop thinking about these blondies!! How are they SO GOOD??? I have made blondies before in the past and was not a fan of them but you have completely changed my mind. I can't wait to make them again!
Cambrea Gordon says
I am so glad to hear that you enjoyed them! Thanks so much for leaving a review 🙂
Tracy says
I just made these with my mom, and they are ABSOLUTELY DELICIOUS! Your video came up on my Instagram newsfeed, and now I can’t wait to see what other recipes of yours I will try!
Cambrea Gordon says
Thanks so much Tracy! I can't wait to see what you make next 🙂
Barbera says
I'm so glad I made these because they are hands down the best blondies I've ever had! They tasted exactly like blueberry crumble and everyone loved how delicious they were. Can't wait to make them again.