Preheat your waffle iron. In a large bowl, whisk together the flour, baking powder, cinnamon, and salt.
Make a well in the center and add the milk, applesauce, melted butter, egg yolks, and vanilla extract. Stir until just combined. A few lumps are fine.
In a separate bowl, beat the egg whites with an electric mixer until stiff peaks form, about 2-3 minutes on high speed.
Gently fold the whipped egg whites into the batter using a spatula. Use big, slow scooping motions from the bottom up. Do not stir or whisk.
Cook the Waffles
Lightly grease the preheated waffle iron with cooking spray. Pour about ½ cup of batter onto the iron (adjust based on your waffle maker size).
Close the lid and cook for 3-5 minutes until the warmth stops and the waffle is golden brown. Do not open the iron too early.
Remove the waffle and place directly on an oven rack at 200°F to keep warm while you cook the remaining batter.
Serve
Serve warm with maple syrup, fresh fruit, warm cinnamon apples, or your favorite toppings.
Notes
Whole wheat flour: Whole wheat pastry flour gives the lightest result. Regular whole wheat works but produces a denser waffle. All-purpose flour makes the crispiest waffles.
Egg whites: Don't skip the whipping step. It's what makes these waffles fluffy instead of flat.
Freezer-friendly: Cool completely, freeze in a single layer on a sheet pan, then transfer to freezer bags. Reheat straight from frozen in the toaster.
Dairy-free: Use melted coconut oil instead of butter and any plant-based milk.
Vegan option: Replace each egg with ¼ cup applesauce and skip the whipping step. Waffles will be denser but still delicious.