For the applesauce and marzipan tartlets, preheat the oven to 170 ° C. Separate the eggs. Beat the egg yolks with sugar, vanilla sugar, salt and the hot water. The mass must be very white. In another bowl, beat the egg whites until stiff. Pull the egg whites into the egg yolk mixture. Briefly fold in the sifted flour, cornstarch and 1 teaspoon baking powder. Line the bottom of a springform pan with baking paper, pour in the batter and bake for 40 minutes.
Allow to cool, then cut horizontally into three parts. Roll out the marzipan between two cling films and cut out 10 circles. Cut out 15 circles from the biscuit base. Beat the cream with a little sugar until stiff. Dissolve the gelatine according to the instructions and add 2/3 of the cream and 1/3 to the applesauce. Then layer in a sideboard: biscuit, marzipan, cream, applesauce, biscuit, whipped cream, applesauce, biscuit and, as a lid, marzipan. Then chill.
For the decoration, melt the dark chocolate over a water bath, pour it into small grids on baking paper and allow to cool.