Whisk together the flour, sugar, and baking powder in a large bowl.
Stir together the egg yolks, milk, butter, and vanilla in a large measuring cup. Stir into the dry ingredients until combined.
Whip the egg whites until stiff peaks form. Fold gently into your batter until incorporated.
Heat a waffle iron and lightly mist with cooking spray. Spoon 3/4 cup batter onto the heated surface. Cook until crisp. Top with butter and syrup and enjoy.