Pre-heat your waffle maker.

Combine the flour, cornstarch, salt and baking powder in a bowl.

Combine the egg yolks, buttermilk, milk, vegetable oil and vanilla extract (if using) in another bowl or measuring cup.

In a third bowl, whisk the egg whites to soft peak stage. Add the sugar and beat until the whites are shiny.

Pour the wet ingredients into the dry ingredients and stir just until combined, but still a little lumpy. Fold in the egg whites until no streaks of white remain.

Grease your waffle iron if necessary and pour in enough batter to just cover the bottom of the waffle plate. Close the waffle maker and cook until the waffle is browned and crispy. Flip the waffle over in the waffle maker and cook for a minute longer.

Remove the waffle from the iron and keep warm in a 200ºF oven, directly on the oven rack, until you’re ready to serve all the waffles. Do not put them on a plate, a baking sheet or stack them on each other.

Serve with maple syrup, berries, butter, or any other of your favorite toppings.