Stir the soft fat and pieces of marzipan until foamy. Gradually add the sugar and eggs. Keep stirring until the sugar has dissolved and the mixture is light-creamy. Add the cooking oil. Mix in flour and baking powder and stir in. Pour in enough milk so that the dough falls from the whisk, tearing it heavily. Cut the chocolate into pieces and fold in. Pour the batter into a well-greased cup cake tin (1.5 liter capacity).
Bake cakes in a preheated oven at 175 ° C top / bottom heat for about 60 to 70 minutes. Let the cake cool down.
Roughly chop the couverture and melt it. Place a wire rack on a piece of aluminum foil. Place the cake on the grid and cover evenly with the couverture. Let it become solid.