Cake: – 2 1/2 c. flour, + 1 Tbsp. – 2 tsp. baking powder – 1/2 tsp. salt – 1 c. (2 sticks) butter, room temperature – 1 c. light brown sugar – 1 c. granulated sugar – 4 large eggs – 1 tsp. vanilla – 1 c. sour cream – Juice of 1 lemon, (about 1/4 c.) – 2 c. blueberries (fresh or frozen) – Zest of 1 lemon (about 1 - 2 Tbsp.)
Streusel Topping: – 1/3 c. light brown sugar – 2/3 c. flour – 1/3 c. butter, softened, not melted Lemon Glaze: – Juice of 1 lemon – 1 - 1 1/4 c. powdered sugar