Preheat oven to 350°F (175°C) and line a large baking sheet with parchment paper.

In a large mixing bowl, mash the bananas with a fork until they reach a smooth consistency.

Add the egg, peanut butter, and vanilla extract to the mashed bananas and whisk until fully emulsified.

Incorporate the rolled oats, protein powder, cinnamon, and baking powder, stirring until a thick, uniform dough forms.

Gently fold in the dark chocolate chips.

Divide the mixture into 8 equal portions (approximately 2 cookies per serving) and place on the baking sheet.

Flatten each dough ball slightly with the back of a spoon, as the cookies will not spread during baking.

Bake for 10 to 12 minutes until the edges are firm and slightly golden.

Remove from the oven and allow to cool on the baking sheet for 5 minutes to set before transferring to a wire rack.