Combine oat flour, tapioca starch, baking soda, and salt in a medium bowl.
Combine buttermilk, oil, maple syrup, vanilla, eggs and banana in another medium bowl.
Add buttermilk mixture to flour mixture and stir well to combine. Stir in mini-chocolate chips.
Preheat waffle iron according to manufacturer's instructions.
Pour batter onto waffle iron when hot and cook until done.