In a large bowl, whisk together oats, oat flour, brown sugar, baking powder, baking soda, cinnamon, and salt.
In a medium bowl, whisk together mashed bananas, egg, peanut butter, and vanilla.
Add the wet ingredients to the dry ingredients, and stir until just combined.
Fold in the chocolate chips.
Drop by golf ball-sized scoops onto parchment paper-lined baking sheets.
Bake at 350 degrees for 12-15 minutes, or until cookies are lightly browned.
Remove to wire racks to cool.
These are great warm from the oven, but also at room temperature, and even refrigerated.
Store in a cool, airtight container.