Mix the butter with sugar, vanilla sugar and salt until frothy, add the eggs one by one, stir until smooth. Now mix the flour with the baking powder and stir in. Add the rum and stir in.
Place the dough on a baking sheet lined with baking paper and smooth it out (the deeper one is best because the cake will rise very much), cover with the prepared fruit and bake for 30 minutes on the middle shelf in the oven preheated to 180 °.