Melt the butter and let it cool down a little. Finely crumble the biscuits and mix them with the butter. Pour the mixture into a greased springform pan (26 cm Ø) and press to a flat base. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 15 minutes. Let cool off.
Wrap aluminium foil around the lower edge and bottom of the springform pan. Chop the chocolate and melt carefully over a hot water bath. Let cool down a little. Mix cream cheese, quark, sugar, vanilla sugar, orange baking, starch and eggs with the whisk of the hand mixer until smooth. Stir in chocolate. Pour the mixture into the mould. Bake at the same temperature for about 1 hour. Cover the last 30 minutes with aluminium foil. Let the cake cool down on a cake rack. Heat the icing in hot water for about 10 minutes.
Bake at the same temperature for about 1 hour. Cover the last 30 minutes with aluminium foil. Let the cake cool down on a cake rack. Heat the icing in hot water for about 10 minutes. Spray the icing directly from the bottle onto the rim. Let it dry. Whipped cream tastes good with it
waiting time approx. 2 1/2 hours