Preheat the oven to 350 degrees F (180 degrees C).
Mash the banana in a bowl until smooth.
Add in the oats, peanut butter, and cinnamon. Mix until well combined.
Fold in the chocolate chips.
Press this mixture into a parchment paper lined loaf pan. Use a spatula to flatten and smooth out the top.
Sprinkle more chocolate chips on top if desired.
Bake for 25 minutes, or until the edges are golden brown.
Allow it to cool completely before slicing into bars.
