Finely chop the couverture and melt over a warm water bath. Beat butter, sugar, vanilla sugar, salt and liquid chocolate coating with the whisk of the hand mixer for approx. 4 minutes until creamy. Add egg and milk and fold in. Mix flour, cocoa and walnuts and fold into the butter mixture with a whisk
Lightly grease the troughs of 2 silicone mats (per mat 15 troughs of 4 cm Ø). Fill the dough with a tablespoon into the hollows and smooth them down. Place the silicone mats on a baking tray and bake in the preheated oven (electric range: 175 °C/ convection oven: 150 °C/ gas mark 2) on the middle shelf for 12-15 minutes. Allow the ring cake cookies to cool completely in the mat, then carefully press them out
Finely chop the white couverture and melt it over a warm water bath, stirring from time to time. Sprinkle half of the gugelhupfs with white couverture using a spoon and allow to dry
Layer Guglhupfcookies between layers of parchment paper in tin cans. Stored in a cool and dry place, they keep for about 3 weeks.
Dust the undecorated half of the Guglhupfs with icing sugar before serving
waiting time approx. 1 1/2 hours