2 cups all purpose flour
1/2 tsp salt
2 tbsp sugar
1 1/2 tsp baking soda
1 3/4 cups buttermilk
2 eggs, separated
1/2 stick butter, melted and cooled
1/2 tsp vanilla extract
Mix all the dry ingredients. Combine the buttermilk, egg yolk, then stir in the vanilla, and melted butter.
Beat the egg whites with a mixer until they form soft peaks. Fold into batter.
Ladle onto waffle iron and let cook about 3-5 minutes. Remove waffles to a plate lined with a towel and cover with towel to keep them warm and moist.
This made 22 waffles when I doubled the recipe.