Blueberry Breakfast Cake

1 stick unsalted butter, room temp
Zest from a large lemon
1 cup sugar, plus some for sprinkling
1 egg, room temp
1 t vanilla
1 3/4 cups flour, plus 1/4 cup separated
2 t baking powder
1/2 cup buttermilk

1. Preheat oven to 350.

2. Cream butter, lemon zest and sugar with mixer until fluffy. Add egg and vanilla and beat until combined.

3. In separate bowl, toss blueberries with 1/4 cup flour.

4. In yet another bow, whisk together 1 3/4 cups flour, baking powder and salt. Add half of flower mixture to batter and stir until combined. Add all the buttermilk and stir. Add remaining flour and stir until absorbed. Fold in the blueberries, discarding remaining flour.

5. Grease 8-in square baking pan and spread batter into the pan. Sprinkle batter with 1T sugar.

6. Bake for 40-45 minutes until toothpick comes out clean.