Preheat the oven at 175 degrees Celsius.
Start to do the bottom by Smash the graham biscuits to crumbled with an hand mixer.
Melt the butter and mix it with the the biscuits. Add the cacao powder and mix well.
Place a baking paper on the bottom of a baking form with removable edges. Press out the biscuitt mixture evenly on the paper.
Put the cake bottom in the middle of the oven for 10 minutes.
Time to do the filling. Start by melting the chocolate on low heat in a casserole.
With an electrical mixer whip the cream cheese, sugar and vanilla sugar very soft. Continue to whip by adding the eggs one by one.
While still wipping add the melted chocolate.
Take out the bottom from the oven. Pour the batter in the cake form and place in the oven for 40 minutes. Take out the cake and let it cool down.
Time to make the frosting. Mix the margarine soft with an electrical mixer. Add the cream cheese and mix it well. While whipping add the cacao powder, icing sugar and vanilla sugar.
Spread evenly the frosting on the cake, and place it cold in the fridge for minimum 4 hours.