Coarsely grate the chocolate. Separate eggs. Beat egg whites until stiff. Cream butter, 80 g sugar, 1 packet vanilla sugar and salt. Stir in the egg yolks one by one. Mix hazelnuts, chocolate and baking powder, stir in. Fold in 2 portions of beaten egg white. Line the bottom of a springform pan (26 cm Ø) with baking paper. Fill in the dough and smooth it down. Bake in the preheated oven 2nd shelf from below (electric oven: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 30 minutes. Let the base cool down on a cake rack (approx. 2 hours)
Soak gelatine in cold water. Peel oranges so that the white skin is completely removed. Remove the fillets with a sharp knife between the parting skins. Squeeze the juice from the membranes and collect it (approx. 300 ml). Bring the orange juice, 50 g sugar, 1 packet of vanilla sugar, Orange Back and orange liqueur to the boil and remove from the heat. Hang the mulled wine seasoning in the hot juice, cover and let it steep for 10-15 minutes. Remove the bag. Squeeze the gelatine and dissolve in the hot punch. Let the orange punch cool down and put it in a cool place for about 30 minutes
Remove the chocolate-nut base from the springform pan, remove the baking paper. Cut the base horizontally once. Place a cake ring around the lower cake base
Remove 16 orange fillets for decoration and cover and chill. Dab the remaining orange fillets dry with kitchen paper. Whip 500 g cream until stiff. When the orange punch starts to gel, stir in the cream in portions. Pour approx. 1/3 of the cream on the bottom base and smooth it down. Spread orange slices on top and spread the rest of the cream on top. Cover with the second cake layer and put the cake in a cool place overnight
Roughly chop the chocolate coating and melt over a warm water bath. Allow to cool slightly and spread as a thin layer on a marble board or the back of a baking tray. Allow to set in a cool place. Use a spatula to form long rolls and put them in a cool place
Whip 400 g cream and 1 packet of vanilla sugar until stiff. Spread half of the cream all around the cake. Put the rest of the cream in a piping bag with a large star-shaped spout. Decorate the cake with cream tuffs, chocolate rolls and orange filets. Keep cool until serving
waiting time approx. 13 hours