1Preheat waffle iron to medium high heat.
Sift together flour, sugar, baking powder, baking soda, and salt into a large bowl.
2In a medium bowl, whisk together buttermilk, egg yolk, vanilla extract, vanilla bean paste or seeds from one vanilla bean and oil til smooth. Whisk in club soda. Gently whisk the wet ingredients into the dry ingredients just til smooth.
3In small clean bowl with clean beaters, beat egg whites til they hold firm peaks. Gently fold into the batter til well blended. Pour batter onto waffle iron and cook til deeply golden. Serve waffles at once.
The longer the waffles cook, the crisper they will be. if you notice a few pale spots, let them continue to cook til they're evenly browned all over. Makes 8 seven inch waffles