In a small blender, add the oats, baking powder, chia seeds, banana and milk. Pulse until smooth.
Pour most of the batter into a ramekin, reserving around 2-3 tablespoon of batter scoop the Nutella into the centre of the ramekin, then top with the reserved batter. Sprinkle with hazelnuts.
Bake in the preheated oven for 20 minutes. Place a piece of chocolate on top and enjoy!
Notes
You can put the chocolate on top of the blended oats before putting it in the oven as well.