Lightly spoon flour into dry measuring cups; level with a knife. Combine flour, baking powder, baking soda, salt, and cinnamon in a medium bowl; stir with a whisk. Combine buttermilk and next 5 ingredients (through applesauce) in a small bowl. Add milk mixture to flour mixture, stirring just until combined. Stir in crystallized ginger.
Beat egg whites with a mixer at high speed until soft peaks form. Gently fold egg whites into batter.
Coat a waffle iron with cooking spray, and preheat. Spoon about 1/3 cup batter per 4-inch waffle onto hot waffle iron, spreading batter evenly to edges. Cook for 5 minutes or until steaming stops, and repeat procedure with remaining batter.
I really liked these waffles as a change of pace. However, as finely as I minced the ginger, unless you really like ginger, it's a bit much. My daughter took the time to pick them out because it was too much. They're great the next day though. Just throw in a convection toaster oven and toast for a few minutes. I topped them with a cream cheese frosting that balanced out the ginger's spiciness.
We liked these a lot. I left the amount of ginger alone and just bumped up the cinnamon as suggested by another reviewer. I used all whole-grain flour (white wheat) and accidentally omitted the applesauce, but the batter seemed to have just the right consistency without it. After mixing the wet and dry ingredients I let the buttermilk react with the soda while I minced the ginger. They turned out hearty but crispy and tasted very much like gingerbread. I served these with sauteed sliced apples, and my visiting mother declared them very good. I will be keeping this recipe for use over the holidays.