7/8 cup + 1 T. sugar
2 cups flour
2 tsp. baking powder
1 tsp. kosher salt
2 cups fresh blueberries
Cream butter with lemon zest and 7/8 cup of the sugar until light and fluffy.
Add the egg and vanilla and beat until combined.
Meanwhile, toss the blueberries with ¼ cup of flour, then whisk together the remaining flour, baking powder and salt.
Fold in the blueberries.
Grease a 9-inch square baking pan (or something similar) with butter or coat with non-stick spray.
Spread batter into pan.
Sprinkle batter with remaining tablespoon of sugar.
Bake for 35 minutes.
Check with a toothpick for doneness.
If necessary, return pan to oven for a couple of more minutes.
Let cool at least 10 minutes before serving.