Preheat the stove to 200 °C. Core the apples generously from the stem end without cutting them open. Cut off the top quarter. Place the apples on a roasting plate. Cut the vanilla pod lengthwise. Gently remove the small seeds and rub them into the bare flesh of the apples. Then spread three tablespoons of sugar evenly on top (for all four apples together!).
Cut the two vanilla pod halves from scratch into two parts each and put the four parts into the apples. Fill the cranberries into the apples. The berries will not fit completely inside the apples – the remaining ones can be draped around the apples for decoration. Sprinkle the berries (on top of the apples) with the remaining sugar.
Bake on the lowest oven rack for 45 min. Spoon the resulting boiling juices over the apples once or twice. Take out on top, remove the vanilla pods. If you like, sweet whipped cream over it form.