Prepare a batter from the ingredients above until baking powder. Spread half of the dough on a baking sheet. Mix the cocoa into the other half and spread this mixture over the light dough. Drain the cherries well and press them lightly into the batter.
Bake the dough in a preheated oven at 180 degrees for about 20 minutes.
Make the custard according to the package insert. Stir the pudding cold (stir carefully every now and then so that no skin forms.) Stir the butter until foamy and fold in the cooled pudding with the mixer, tablespoon at a time. Spread the cream on the cooled cake.
Mix the cocoa, eggs and powdered sugar with the rum. Add the liquid palmin (heat in the pot until it liquefies) and carefully spread over the buttercream.