Step 1

Preheat the oven to 350F. Grease an 8x8-inch baking dish. Set aside.

Step 2

In a small bowl, toss the blueberries with 1/4 cup flour. Set aside.

Step 3

In a large bowl, beat the butter, lemon zest, and sugar together until well-combined, about 2-3 minutes on medium.

Step 4

Mix in the egg and vanilla extract until well-combined.

Step 5

Add the remaining flour, baking powder, and salt.

Step 6

Stir in just until combined. Don't overmix.

Step 7

Add the buttermilk.

Step 8

Stir in just until combined. Don't overmix.

Step 9

Fold in the blueberries just until incorporated.

Step 10

Pour the batter into the prepared pan.

Step 11

Sprinkle with remaining sugar.

Step 12

Bake for 35-50 minutes or until a toothpick inserted in the center comes out clean.

Step 13

Cool 15-20 minutes before slicing and serving.