Grease the springform pan Ø 23 cm and dust with flour. Put the beer in a large saucepan, add the butter and let it melt. Then take the pot off the stove. Now stir in the cocoa and sugar.
In a mixing bowl, whip up the sour cream, eggs and vanilla sugar and add the beer.
Gradually stir in the flour and baking soda until you get a smooth dough. Don`t stir the dough for too long.
Now pour the dough into the baking pan and bake the cake in the oven for approx. 45 - 60 minutes at 180 ° C top / bottom heat. Every now and then, use a toothpick to test whether the dough is through. Then let it cool completely in the pan, as the cake is quite moist.
Meanwhile, carefully whip the cream cheese until it is smooth and soft. Then stir in the powdered sugar and mix everything into a smooth, spreadable cream. Brush the cooled cake loosely with it and sprinkle with chocolate shavings.