Bake at 180°C for about 25-30 minutes. The scent of cocoa that will invade the kitchen will be the sign that the magic is almost ready. Check the cooking with a toothpick: it should come out clean but with a slight hint of moisture.
Once baked, let the cake cool. Sprinkle with icing sugar, and, if you want an extra touch, a sweet drizzle of Nutella as a final decoration.