In a small bowl, combine the almond milk and apple cider vinegar to create vegan buttermilk. Set aside.
In a high-powered blender or food processor, add the rolled oats, applesauce, banana, almond milk/apple cider vinegar mixture, cinnamon, baking powder, and salt. Process until combined. Let it sit for a few minutes to thicken.
Spray the waffle iron with cooking oil and pour in the mixture. (I used 1/3 cup for the mini waffle maker). Cook until browned.