Preheat the oven to 350ºF. Line 2 baking sheets with parchment paper or silpat liners.

In a bowl, whisk together the flour, baking powder, baking soda, salt and cinnamon. Set aside.

In the bowl of a stand mixer, or in a large bowl, cream together the butter, white sugar and brown sugar. Add the egg, followed by the banana and the vanilla.

Stir in the flour mixture along with the oats. Mix just until it starts to come together. It will feel a bit dry at this point.

Add the chocolate chips and continue to mix until it all comes together into a ball.

Using a 1 1/2 tablespoon scoop, divide the dough into 24 balls. Place them about 2 inches apart - 12 cookies on each cookie sheet. With slightly wet hands, lightly press down on the cookies to make a flatter disc.

Bake in the preheated oven until browned along the edges, about 8 minutes.

Remove from the oven and let the cookies cool on the baking sheet for 3 to 4 minutes before removing to a cooling rack to cool completely.