Line the springform pan with baking paper and butter the edge, then put in a cool place.
Preheat the oven to 160 degrees top and bottom heat.
Put the chocolate in pieces together with the butter in a bowl and allow to melt over a hot water bath. Add the sugar, vanilla sugar, salt and ground almonds. Whisk and stir in eggs. Mix the baking powder and flour, sieve and stir in. Then pour the batter into the cake pan.
Bake the cake for 45-50 minutes; it stays slightly creamy on the inside.