Whisk together flour, baking powder, baking soda, salt and sugar in a large bowl.
Add egg yolks, melted butter, buttermilk and vanilla and whisk together into a smooth batter.
In a separate bowl whisk the egg whites until the form stiff peaks and fold into the waffle batter.
Using ½ cup of batter for each waffle, cook according to directions on your waffle maker. I cook mine for 3-4 minutes so that they are crispy on the outside.
Serve immediately or cool on a wire cooling rack and freeze in a ziplock bag. To re-heat, remove from freezer and put in the toaster until warm or re-heat in your waffle maker.