Let the raspberries thaw in a bowl. Mix mascarpone, quark, sugar, vanilla sugar, 1 pinch of salt and 2 tablespoons of liqueur well. Finely chop the chocolate, then fold the chocolate and raspberries with the juice into the cream.
Line the bottom of a mould approx. 16 x 16 cm with half of the lady fingers. Mix 2 tablespoons of liqueur and espresso, drizzle half over it. Spread half of the raspberry cream evenly on top.
Cover with the remaining ladyfingers. Drizzle the rest of the espresso mix over it. Spread the rest of the cream on top. Tiramisu covered and left to cool for at least 4 hours, preferably overnight. The tiramisu will be particularly juicy if you make it the day before.
Dust the tiramisu with cocoa just before serving.