For the dough, mix flour and baking powder and sift into a mixing bowl. Add sugar, vanilla sugar, salt, egg and butter and work well with a hand mixer with dough hook.
Then knead on floured work surface until smooth and refrigerate for about 1 hour. Roll out two-thirds of the dough on a greased springform pan (26 cm).
Form the remaining dough into a roll, place it as a rim on the bottom and press it against the pan to form a rim about 3 cm high. For the filling, peel, quarter, core and dice the apples.
Prepare a pudding from the pudding powder, sugar, vanilla sugar, wine and apple juice according to the package instructions. Immediately stir in the apple cubes and pour the mixture onto the dough. Place the pan on the rack in the oven and bake at approx. 170°C (top and bottom heat, preheated) or approx. 150°C (hot air, not preheated) for about 50 – 60 minutes.
Place the cake in the pan on a cake rack, let cool for about 15 minutes, loosen the springform pan rim and remove. Refrigerate the cake for 3 – 4 hours. Whip the cream with cream stiffener and vanilla sugar until stiff, fill into a piping bag with a serrated nozzle and decorate the edge of the cake with it.
Garnish the cake with pistachio nuts. The pudding can be cooked with 750 ml (3/4 l) apple juice instead of the white wine and apple juice mixture. The cake takes a little longer, but it’s worth it!
