Mix the ingredients for the dough quickly and well and bake on a flat tray for 25-30 minutes at 175 ° C.
When the dough has cooled down, whip the cream, cream stiffener and vanilla sugar until stiff, then fold in the sour cream and distribute it on the dough.
Then roast the walnuts with butter and sugar in a pan and then spread them on the cream mixture. Finally sprinkle the melted chocolate icing over the cake in strips.