Beat the whipped cream with a packet of vanilla sugar until stiff. Drain the mandarins. Mix the mascarpone, quark, sugar and a packet of vanilla sugar together and fold in approx. 2/3 of the cream.
Crumble the chocolate cake in a baking dish, then spread about half of the mascarpone cream on top. Now layer the mandarins on top. Spread the rest of the cream on top and cover with the rest of the cream.
Place in the refrigerator until ready to be eaten. Dust with a little cocoa before serving.