For the short pastry: Knead all ingredients first with the dough hook of the mixer, then with your hands to a smooth dough and put it covered for 30 minutes to cool. Roll out the dough on a little flour and spread it on the bottom of a cake springform pan (28 cm ø). Prick the dough a few times with a fork and bake in a heated oven at 180 degrees, convection oven at 160 degrees, gas mark 3 for about 15 minutes until golden brown.
Cool.
For the sponge cake: separate the eggs. Whip egg whites and 2 tablespoons cold water until stiff. Add sugar and vanilla sugar and continue beating until sugar is dissolved. Fold in egg yolks. Combine flour, cornstarch and baking powder, sift over the top and fold in loosely with a whisk. Fill the dough into a cake springform pan (28 cm ø) lined with parchment paper and bake in a heated oven at 180 °C , convection oven 160 °C , gas mark 3 for about 25-half hours. Cool.
For the topping: drain the cherries well. Separate the eggs. Whip the egg whites until stiff. Mix egg yolks, custard powder and 100 ml milk until smooth. Bring the remaining milk, 500 g whipped cream, sugar and the scraped out pulp of the vanilla pod to the boil. Pour in the mixed custard powder while stirring, bring to the boil briefly and remove from the heat. Whisk in the snow on the spot so that there are no more lumps in the cream. Soak the gelatine in cold water, squeeze it out and let it melt in the warm cream. Cream