Cream butter, sugar and vanilla sugar with the whisk of the hand mixer. Stir in the eggs one by one. Mix flour and baking powder and stir in alternately with the milk. Put half of the dough into a greased, flour-dusted box form (approx. 30 cm long, 1 3/4 litre capacity). Stir chocolate drops, except for 1 tbsp, into the remaining dough, spread on the dough and smooth it down. Sprinkle with 1 tablespoon of chocolate drops. Bake in the preheated oven, 2nd shelf from below (electric oven: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 45 minutes. If necessary, cover with foil about 10 minutes before the end of the baking time
Remove the cake, let it cool in the mould for about 30 minutes, then turn out of the mould and let it cool down on a cake rack. Coarsely chop the chocolate coating and melt over a warm water bath. Stir in oil. Cover the cake with the chocolate coating and refrigerate for approx. 1 hour
Fig. 02: Covering the cake with the chocolate coating. Sprinkle with cocoa and refrigerate for about 1 hour
waiting time approx. 3 hours