2 tsp. lemon zest or more — zest from 1 large lemon
¾ cup sugar + 1 TBSP to sprinkle on top
1 egg, room temperature
1 tsp vanilla
2 cups flour
2 tsp. baking powder
1/4 tsp salt
2 cups fresh or frozen blueberries
½ cup buttermilk*
Preheat the oven to 350F (convection 325F).
Cream butter with lemon zest and 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.
Add the flour mixture to the batter a little at a time, alternating with the buttermilk. 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 (try turbinado if you have it). Bake for 35 minutes. Check with a toothpick for doneness. If necessary, return pan to oven for a couple of more minutes. (Note: Baking for as long as 10 minutes more might be necessary.) Let cool at least 15 minutes before serving.
* If you realized the refrigerator froze the buttermilk (again!), you can use ½ cup yogurt, and ¼ cup milk instead and it will be just as delicious.
Adapted from http://www.alexandracooks.com/2011/06/29/buttermilk-blueberry-breakfast-cake/