Preheat waffle maker and spray with a nonstick cooking spray.Combine all dry ingredients (oat flour through sea salt) in a medium bowl.Add vanilla and almond milk to flour mixture; stir until smooth.Beat egg whites for a couple of minutes and until light and foamy. Gently fold egg whites into batter.Cook batter in preheated waffle iron according to waffle maker instructions.While waffles are cooking, make warm apple topping.