Mash the banana in a small bowl.
Add the egg, oat flour, baking powder, and skyr. Mix until smooth.
Fold in half of the chocolate chips.
Pour into a small ramekin or microwave-safe dish.
Place the dark chocolate square in the center and sprinkle the remaining chocolate chips on top.
Bake at 350°F (175°C) for 15–20 minutes, or microwave for 1–2 minutes, until set.
Let cool slightly and enjoy!
