Preheat the oven to 350°F (175°C) and grease an 8x8 inch baking pan with non-stick spray or parchment paper.

In a large mixing bowl, mash the bananas until a smooth consistency is reached.

Incorporate the egg, peanut butter, and almond milk into the mashed bananas, whisking until homogenous.

Add the rolled oats, protein powder, cinnamon, baking powder, and salt to the wet mixture.

Fold the ingredients together using a spatula until the dry ingredients are fully hydrated.

Stir in the dark chocolate chips until evenly distributed.

Transfer the batter to the prepared baking pan and smooth the top with a spatula.

Bake for 22 to 25 minutes, or until the center is firm to the touch and the edges are lightly browned.

Remove from the oven and allow to cool completely in the pan for at least 15 minutes before slicing into 9 squares.