Cut a lid from the apples, cut out the core generously and place the apples in a greased gratin dish.
Toast the coconut, oat flakes, walnuts with butter and sugar until the sugar is caramelized. Then fold in raisins, rum and whipped cream. Fill the mixture into the apples, spread the rest evenly around the apples. Bake in the oven at 220 °C for 20-30 minutes.