Grease a springform pan with a tube bottom insert (26 cm Ø; approx. 7 cm high) and dust with flour. Break chocolate into pieces. Dice butter. Melt both together in a hot water bath. Cool down a little
Beat the eggs, sugar, vanillin sugar and 1 pinch of salt for about 8 minutes until fluffy. First stir in the chocolate butter bit by bit, then the sour cream and rum flavouring. Mix flour and baking powder, sieve on top and stir in briefly
Spread the dough into the mould. Bake in the preheated oven (electric oven: 175 °C/circulating air: 150 °C/gas: level 2) for about 1 hour. Let cool down for about 10 minutes. Then remove from the mould and let it cool completely
Roast almond slivers without fat, let them cool down. Coarsely chop the whole chocolate coating, melt in a hot water bath with plate-grease. Cover the cake with it and "lard" with the almond slivers. Let the chocolate coating dry