Combine oatmeal, protein powder, baking powder, and salt in a bowl.
Mash the banana and add to the bowl, mixing well.
Add almond milk and olive oil, and mix until the dough comes together.
Shape the dough into rounds and place on a baking sheet lined with parchment paper.
Bake in a preheated oven at 180°C (356°F) for 15 minutes.