Separate eggs. Beat the egg whites and 4 tablespoons of water with the whisk of the hand mixer until stiff, adding 125 g sugar and 1 packet of vanilla sugar. Stir the egg yolks individually into the beaten egg white. Sift the flour, starch, baking powder and cocoa in portions onto the egg mixture and fold in. Line the bottom of a springform pan (26 cm Ø) with baking paper. Pour in the sponge mixture and smooth it down.
Bake in the preheated oven (electric: 175 °C/ gas: level 2) for 20-25 minutes. Loosen the edge with a knife and let the sponge cake cool down on a grid. In the meantime, boil up 50 ml water and remaining sugar in a small pot. Add rum, remove from the heat and let it cool down. Drain 2 cans of mandarin oranges well on a sieve. Halve the sponge cake horizontally in the middle. Sprinkle the sugar-rum solution on the bottom of the sponge cake. Whip 500 g cream with the whisk of the hand mixer. Mix the remaining vanillin sugar and cream setting agent and let it trickle into the cream. Whip until stiff. Fold mandarin oranges into the cream. Place the cake base on a cake plate and close the cake ring around it.
Whip 500 g cream with the whisk of the hand mixer. Mix the remaining vanillin sugar and cream setting agent and let it trickle into the cream. Whip until stiff. Fold mandarin oranges into the cream. Place the cake base on a cake plate and close the cake ring around it. Pour the mandarin orange cream on top, smooth it down and put the cake lid on top of it. Place the cake in a cool place for about 2 hours. In the meantime, pour the remaining mandarin oranges onto a sieve and drain well. Whip the rest of the cream until stiff. Loosen the cake ring and spread the cake all around with cream. Decorate the edge of the cake with a cake comb as desired. Decorate with the remaining mandarin oranges and chocolate rolls as desired
Place the cake in a cool place for about 2 hours. In the meantime, pour the remaining mandarin oranges onto a sieve and drain well. Whip the rest of the cream until stiff. Loosen the cake ring and spread the cake all around with cream. Decorate the edge of the cake with a cake comb as desired. Decorate with the remaining mandarin oranges and chocolate rolls as desired