Buttermilk-blueberry Breakfast Cake

Ingredients:
1/2 cup unsalted butter, room temp.
2 tsp lemon zest (1 lemon)
7/8 cup + 1 Tbsp sugar
1 egg
1 tsp vanilla
2 cups flour
2 tsp baking powder
1 tsp salt
2 cups fresh blueberries
1/2 cup buttermilk

Directions:
1. Oven at 350; grease 9" square baking pan (with spray or butter)
2. Cream butter with lemon zest and 7/8 cup of sugar until light and fluffy.
3. Add egg and vanilla
4. Toss blueberries with 1/4 cup flour in separate bowl
5. Whisk remaining flour, baking powder and salt.
6. Add flour mixture to the batter a little at a time, alternating with the buttermilk.
7. Fold in blueberries.
8. Spread batter in pan and sprinkle with Tbsp of sugar.
9. Bake 35 minutes

Recipe found here:
http://www.alexandracooks.com/2011/06/29/buttermilk-blueberry-breakfast-cake/