Preheat waffle iron to medium-high heat setting.
If using eggs: In a small metal bowl, place the egg whites; place the yolks in a separate bowl. Whisk the egg whites until frothy (preferably using an electric mixer). Set aside.
In a large bowl, beat (egg yolks OR applesauce), oil, and vanilla extract together.
In a separate bowl, whisk together all dry ingredients. Add dry ingredients to the large bowl, followed by the milk or protein drink.
Whisk together until only very small lumps remain in the batter, then fold in the egg whites gently, if using eggs.
Scoop ⅔ - ¾ cup of batter into preheated waffle iron. Spread with a silicone spatula to ensure the mixture is evenly distributed. Close the lid of the waffle iron and cook for 5 minutes or when your iron alerts you that the waffle is cooked.
Once cooked, open waffle iron cover and loosen the waffle, if necessary, with a fork or silicone spatula. Remove to a plate to serve or cool while cooking remaining waffles. Serve with confectioner's sugar, syrup or warmed berries.
