Coat the waffle iron grids with cooking spray and preheat the iron according to the manufacture's instructions.
Sift the flour, baking powder, baking soda, and salt onto a square of wax paper (or mix in a bowl). set aside.
In a medium bowl beat the egg whites with an electric mixer until stiff. Set aside.
In a large bowl, beat the egg yolks with a fork. whisk in the buttermilk and oil. Add the flour mixture and stir just until the large lumps disappear. Fold in the egg whites.
Pour 1 cup batter (or the amount recommended by your waffle iron's manufacture) evenly onto the preheated grid. Close the lid and bake until crisp and golden brown. following manufactures instructions. (Leftover batter can be stored in refrigerator for 1 to 2 days.)
Serve with butter and syrup or other toppings as desired.