Line the springform pan with baking paper. Finely chop the rusks in a bag with the rolling pin. Then knead well with 50 g of butter, spread on the springform pan and press firmly. Refrigerate !

Preheat the oven to 180 degrees. Peel and core the apples and dice the pulp.

Mix the quark, 100 g butter, 2 packets of vanilla pudding, 200 grams of sugar, 1 packet of bourbon vanilla sugar, 6 eggs, 1 teaspoon of baking powder and a squirt of lemon juice well.

Now mix the quark mixture with the diced apples and place in the springform pan and leave in the oven at 175 to 180 degrees for about 60 minutes. After 45 minutes, prick the cake with a small wooden stick and check whether the cake is good! No dough should stick to the wood.