Separate eggs, beat egg whites with 3 tablespoons of cold water until stiff. Add sugar and 1 sachet of vanilla sugar. Beat the egg yolks one after the other. Mix flour, cocoa, cornstarch and baking powder, sieve onto the egg foam and fold in. Grease the bottom of a springform pan (26 cm Ø) and dust with flour. Pour in the mixture and smooth it down.
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 20-25 minutes. Let it cool down. Cut the sponge cake in half horizontally and place a cake ring around the lower cake base. Heat the orange marmalade and spread half of it on the bottom cake layer. For the cream, whip cream with 3 sachets of vanilla sugar and cream firming agent in 3 portions until stiff. Set aside 1/3 of the cream for spreading. Fold the chocolate shavings, except for a little bit for sprinkling, into the rest of the cream. Spread the cream on the cake base and place the sponge lid on top. Remove cake ring. Spread the rest of the cream all around the cake. Cut the mango off the stone. Peel the flesh and cut into slices.
Fold the chocolate shavings, except for a little bit for sprinkling, into the rest of the cream. Spread the cream on the cake base and place the sponge lid on top. Remove cake ring. Spread the rest of the cream all around the cake. Cut the mango off the stone. Peel the flesh and cut into slices. Cover the cake with mango wedges and spread with the remaining orange jam. Sprinkle with remaining chocolate shavings
Waiting time approx. 20 minutes