Deluxe Waffles

In a large bowl sift together the flour, baking powder, salt, and sugar. Make a well in the center of the bowl.
In a separate bowl, mix together the egg yolks, milk, and oil. Pour into well of flour mixture and stir well. Stir just until ingredients are moistened.
In a small bowl beat egg whites until stiff. Fold into batter.
Cook batter in waffle iron.