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These Blueberry Crumb Blondies have browned butter, fresh blueberries, and a fudgy, chewy texture. The crumble topping makes these taste just like blueberry crumb muffins!

Blueberry Crumb Blondies

Course Dessert
Prep Time 15 minutes
Cook Time 20 minutes
Total Time 35 minutes
Servings 16 bars
Author Rachel Conners


  • ½ cup (1 stick) unsalted butter
  • 1 cup light brown sugar packed
  • 1 large egg
  • 1 tablespoon vanilla extract
  • 1 cup all-purpose flour
  • 1 teaspoon cinnamon
  • ¼ teaspoon kosher salt
  • ½ cup fresh blueberries

For the crumble

  • ¾ cup all-purpose flour
  • ¼ cup light brown sugar
  • ½ teaspoon baking powder
  • 4 tablespoons ½ stick unsalted butter, melted


  1. Preheat oven to 350°F. Line an 8x8" pan with aluminum foil or parchment paper and spray with cooking spray; set aside.
  2. Place butter in a medium saucepan and heat over medium-low to medium heat. Butter will melt, then begin to bubble and foam. Brown specks will begin to form in the bottom of the pan, with a white foam will appear on top of the melted butter. Stir the butter very frequently to prevent burning. It should smell very nutty and the butter in the bottom of the pan should have brown flecks in it. This process should take 2-4 minutes. Butter can go from being browned and nutty-smelling to burnt and inedible in less than one minute. Watch for the brown specks and once you see them, remove the pan from the burner, continuing to whisk for another 30 seconds. Transfer butter into large mixing bowl and allow it to cool for a few minutes.
  3. Add the brown sugar to the browned butter and whisk to combine. Add the egg, vanilla, and whisk to combine. Add the flour, salt, and cinnamon and stir until just combined, taking care not to over-mix. Fold in the blueberries. Pour batter into prepared pan, smoothing it lightly with a spatula or offset knife.
  4. Make the crumble topping. In a medium bowl, combine the flour, brown sugar, and baking powder. Stir in the melted butter, then press the mixture together to form clumps. Sprinkle evenly on top of the bars.
  5. Bake for about 20 minutes, or until the bars are set and golden brown. The edges will be slightly pulling away from sides of pan. Allow bars to cool for at least 2 hours before slicing and serving into 16 squares. I like to refrigerate them before cutting to make them easier to cut. Bars can be stored in an airtight container at room temperature or in the refrigerator for up to 1 week, or in the freezer for up to 3 months.