Preheat your waffle iron and lightly coat with nonstick cooking spray.
In a large mixing bowl, whisk together the flour, cocoa powder, sugar, baking powder, baking soda, cinnamon, and salt.
Using a hand mixer, beat the egg whites in a medium bowl until stiff peaks form. Set aside.
In another medium bowl, thoroughly mix the egg yolks, vegetable oil, milk, and vanilla extract.