In a large bowl beat together the egg yolks and sugar until sugar is completely dissolved and eggs have turned a pale yellow.

Add the vanilla extract, melted butter, and milk to the eggs and beat to combine.

Combine the egg-milk mixture with flour, baking powder, and salt and beat just until blended. Do not over mix.

In another bowl, beat the egg whites until soft peaks form, about 1 minute.

Using the rubber spatula, gently fold the egg whites into the waffle batter. Do not overmix!

Coat the waffle iron with non-stick cooking spray and pour enough batter in iron to just cover waffle grid. Close and cook as per manufacturer''s instructions until golden brown, about 2 to 3 minutes. Serve immediately.

Makes 14 4x4" waffles.