Preheat the oven to 180°C (356°F).
Mash the banana.
In a bowl, combine the mashed banana, eggs, protein powder, cocoa powder, almond flour, and baking powder. Mix well.
Add dark chocolate chips and mix thoroughly.
Divide the batter evenly into muffin molds.
Bake in the oven at 180°C (356°F) for 15–20 minutes.