Step 1

Preheat the oven to 350℉ and line an 8x8" baking pan with parchment paper.

Step 2

In a medium bowl, stir together the flour and baking powder until evenly combined. Then, add the blueberries to the bowl and toss them in the flour mixture until well coated. This coating of flour prevents them from sinking to the bottom of the blondies.

Step 3

In a separate large bowl, whisk together the granulated sugar, lemon zest, and melted butter until smooth. Then, whisk in the egg and vanilla extract until fully combined.

Step 4

Pour the dry ingredients into the wet ingredients. Stir gently with a spoon or rubber spatula until all ingredients are just combined. Do not over-mix the batter, and be careful not to crush the blueberries!

Step 5

Transfer the thick blondie batter to the prepared baking pan. Spread the batter evenly around the pan and into the edges. Gently press extra blueberries into the top of the batter before baking, if desired.

Step 6

Bake the blondies for 40-50 minutes or until the edges of the blondies are lightly golden. A toothpick inserted in the center of the pan should come out clean, or with a few moist crumbs. If a toothpick comes out with wet batter, keep baking the blondies until the toothpick is clean.

Step 7

Let the blondies cool in the pan. While they cool, mix the icing. Whisk together the powdered sugar with one teaspoon of lemon juice at a time. Slowly add more lemon juice to achieve a "drizzle" consistency. If too thin, add more powdered sugar to thicken it slightly.

Step 8

Drizzle the lemon icing evenly over the cooled blondies. Slice into 12 bars and enjoy!