Start by preheating the oven to 350°F. Line an 8x8 baking dish with parchment paper.
In a medium bowl, mash the bananas with a fork. Mix in the maple syrup, peanut butter, vanilla extract and whisk in the egg.
To the same bowl, add in the rolled oats, flour, cinnamon, salt and baking powder. Mix together until combined.
Fold in the chocolate, reserving some for topping. Spread into the lined baking dish then top with the remaining chocolate before baking.
Bake for 25-28 minutes or until the middle is set and the edges are slightly browned.
Allow to cool on a wire cooling rack, slice into 9-12 squares and enjoy!