Peel 3 oranges and separate them into individual columns. Cut orange slices in half crosswise. Simmer with jam, 50 g sugar and aperol in a saucepan for about 20 minutes until the liquid is almost boiled away. Squeeze the remaining orange.
Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Grease the recesses of a muffin tray (12 recesses). Cream 125 g butter, 75 g sugar and vanilla sugar with the whisks of the mixer.
Stir in the eggs one by one. Mix flour and baking powder. Stir orange juice into the butter-sugar mixture.
Spread the orange compote into the hollows. Add the dough and bake in a hot oven for about 20 minutes.
Remove and immediately turn over onto a baking tray or a large cake plate. Serve hot or cold, e.g. with vanilla sauce.