Thaw the raspberries. Roughly chop the white chocolate. Mix the quark with 2 tablespoons of sugar. Whip the cream until stiff.
Brush half of the raspberries vigorously through a fine sieve with a tablespoon. Mix the raspberry sauce with the vanilla sugar and the remaining raspberries. Fold the whipped cream into the quark. Pour the raspberry mixture on top and fold in loosely. Layer alternately with the chocolate in 4 glasses.