Mix oat flour and almond flour in a bowl.
Add unsweetened cocoa powder, baking powder, and salt; mix well.
Mash a ripe banana and add it to the mixture.
Add honey and egg whites, mixing everything thoroughly.
Chop dark chocolate into small pieces and fold into the dough.
Line a baking pan with parchment paper and scoop bite-size portions onto it.
Bake for 15 minutes in a preheated oven at 180°C (356°F).
Let cool before serving.