How to Make It
Heat a waffle iron to medium-high according to manufacturer's instructions. Stir together flour, sugar, baking powder, and cinnamon in a large bowl. Set aside.
Whisk together buttermilk, coconut oil, eggs, and egg white in a separate bowl. Add buttermilk mixture to flour mixture, and stir just until blended.
Lightly coat waffle iron with cooking spray. Spoon 1/3 heaping cup batter onto waffle iron. Cook until lightly browned, about 4 minutes. Repeat with remaining batter; serve immediately. (If not serving immediately, keep waffles warm in a 200°F oven.)