Beat the butter and sugar until frothy. Add eggs and pudding powder and stir. At the end stir in the quark well. Put the dough (it`s pretty runny) in a well-greased springform pan (28 or 26cm). Bake at 170 ° C (fan oven) for about 1 hour. Let cool in the mold.
It is better to check once more whether the cake is already good (stick test) so that it does not get too dark.