In a large mixing bowl, combine the rolled oats, oat flour, baking powder, pumpkin pie spice, cinnamon, and salt. Give it a good stir to mix everything together.
In a separate medium bowl, whisk the egg, then add the pumpkin purée, mashed banana, maple syrup, and vanilla extract. Stir until smooth and well combined.
Pour the wet ingredients into the bowl with the dry ingredients and mix until everything is evenly incorporated. Gently fold in the chocolate chips, if using.
Spread the batter evenly into the prepared baking pan, smoothing out the top. For a little extra chocolate in every bite, sprinkle a few more chocolate chips over the surface.