Preheat the oven at 175 degrees Celsius.
Start by preparing the cake by butter round baking form with removable edges, sprinkle it with flour.
Put sugar, egg and vanilla sugar in a bowl and whip it to a white fluffy mixture.
Add the rest of the ingredients for the cake and mix well.
Pour the batter in the baking form.
Place in the lower part of the oven for 40 minutes.
Take the cake out and let it cool down. Then make many small holes all over the cake.
Time to do the filling by mixing all the 3 different kind of milk in a bowl.
Pour gently the milk mixture over the cake. Put the baking form on a deep plate. Place the cake in the fridge for minimum 6 hours, or if you have time over the night.
Time to decorate the cake by whip the whip cream and put it evenly on and around the cake. Sprinkle the cacao powder on the cake before serving it.