This recipe comes courtesy of the Mountain Fare Inn in Campton, New Hampshire.
Preheat waffle iron.
In a bowl, whisk together flours, baking powder, brown sugar, cinnamon, and salt.
In the bowl of a stand mixer, beat egg whites until soft peaks form. Set aside.
In another bowl, whisk together egg yolks, milk, butter, and vanilla. Stir egg yolk mixture into dry mixture until combined (some lumps are fine). Gently fold in egg whites, then fold in apple.
Brush melted butter over hot waffle iron. Spoon batter into waffle iron and cook for 3 to 5 minutes, or until nicely browned.