Whip butter, sugar, vanilla sugar for approx. 10 minutes until creamy white. Stir in the eggs one at a time. Stir in 150 g of melted chocolate. Mix the flour and baking powder, sieve and stir in alternately with the milk. Fold in the berries.
Pour into a greased form and bake at 175 ° C for 50 - 60 minutes. Let cool and cover with the rest of the melted chocolate.