Mix all dry ingredients in a bowl with a whisk. Add the milk and 3 tablespoons of the plum jam and stir to a smooth mass. Preheat the oven to 200 ° C. Spread the mixture on a baking sheet lined with baking paper and bake for about 15-20 minutes.
Immediately brush the hot cake with the remaining jam (3-5 tablespoon) and then cover with chocolate icing. Chill something.
Tip: The base is rather thin, depending on the baking tray. If you want a thicker batter, you can of course bake the specified amount in a springform pan.