A great cake recipe for any occasion:
Cream butter until smooth and gradually beat in vanilla sugar, salt, sugar and lemon zest until combined. Gradually fold in eggs (about 1/2 minute per egg).
Combine flour with cornstarch and baking powder, sift and fold in by tablespoonfuls on medium speed. Fill the dough into a greased springform pan (approx. 28 cm ø), smooth it out and bake at 175-200 °C for about 20 minutes. Cut the cooled cake base once in half.
Peel, quarter and core the apples and cut each quarter into 2-3 wedges.
Boil wine with sugar, vanilla sugar and lemon peel and add apple slices in portions. Steam until not too soft. Remove with a slotted spoon, cool and pour the liquid through a sieve.
Mix gelatin with cold water in a small saucepan and let stand for 10 min to swell.
Mix cornstarch with sugar and the liquid in a saucepan, fold in egg yolks and heat, beating continuously, until a bubble rises. Stir in the swollen gelatin until it melts. Fold in juice of one lemon, cool and whisk occasionally.
As soon as the mixture starts to thicken, fold in Calvados, whip whipped cream until stiff and fold in.
Cover the bottom of the cake with the apple slices, place a springform cake ring lined with parchment paper around it.