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.

Pour the wet ingredients into the bowl with the dry ingredients and stir until just combined. Do not to overmix.

Gently fold the beaten egg whites into the batter, maintaining as much air as possible.

Pour the batter onto the preheated waffle iron, spreading evenly and cook according to the manufacturer's instructions. The waffles are cooked when they are golden brown.

Serve the waffles hot with butter, syrup, powdered sugar, or any other topping. DEVOUR!