Step 1

Place egg whites in a small bowl; let stand until needed. Preheat oven to 350°.

Step 2

In a large bowl, mix flour and sugar; cut in butter until crumbly. Reserve 3/4 cup mixture for topping. Add baking powder, milk and egg yolks to remaining mixture; beat until blended. With clean beaters, beat egg whites until soft peaks form; fold into batter.

Step 3

Transfer to a greased 13x9-in. baking dish. Sprinkle with blueberries and reserved topping. Bake until golden brown and a toothpick inserted in center comes out clean, 30-35 minutes. Cool on a wire rack.