Prep your waffle iron with cooking spray, and heat to medium heat.
Using a sifter combine the flour, baking powder, salt, and sugar into a medium bowl.
Using an electric mixer and a separate bowl, mix the egg whites until stiff peaks form. Stiff peaks take about 2 minutes and the peaks should stand straight up when you life the beaters.
In a third bowl, mix the egg yolks, milk, oil and vanilla extract. Once combined add the flour and mix just until incorporated. It's important not to overmix your batter.
Once mixed, fold in your egg whites. When I folded in the egg whites I found they wouldn't combine quite right, I ended up whisking them a bit to incorporate better. I'm sure that's a cardinal sin of cooking but they just wouldn't fold into the batter for me, so just be patient if you can!
Waffles need about a 1/2 cup of batter poured into the waffle iron. Cook until the waffle is golden brown and be sure to spray cooking spray between each waffle.
Serve with the homemade Strawberry Butter and Vanilla Maple Syrup.