Atlanta Waffles

1 1/2 cups sifted flour
3 teaspoons baking powder
2 teaspoons granulated sugar
1/2 teaspoon salt
1 cup milk
2 egg yolks, well beaten
4 tablespoons melted butter
2 egg whites, beaten stiff

Sift dry ingredients together. Stir in milk gradually. Stir in egg yolks and butter. Gently fold in egg whites. Preheat waffle maker. Cook waffles following manufacturer's directions, 4 to 5 minutes each.