
Blondies are often overlooked in lieu of brownies, but when it comes to fresh spring flavors, these lemon-blueberry blondies can't be beat.
Preheat oven to 350°. Grease a 9" square baking pan cooking spray. Line with parchment, leaving an overhang on 2 opposite sides. Grease parchment with cooking spray.
In a medium bowl, whisk brown sugar, butter, vanilla, lemon zest, baking powder, and salt until well combined. Stir in eggs until well combined. Add flour and stir just until combined. Add 3/4 cup blueberries and fold just to distribute.
Scrape batter into prepared pan; smooth top. Sprinkle with remaining 1/4 cup blueberries.
Bake blondies until golden and a tester inserted into the center comes out clean, about 35 minutes. Transfer pan to a wire rack and let cool completely.
In a small bowl, whisk powdered sugar and lemon juice, adding water a few drops at a time, until a drizzling consistency is reached. Drizzle glaze over cooled blondies. Let set 15 minutes.
Using parchment overhang, lift blondies out of pan and transfer to a cutting board. Slice and serve.