Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Cut dates into small pieces. Pluck marzipan. Knead with almonds and dates. Wash, halve and core apples and place in an ovenproof dish.
Spread the marzipan mixture on the apples. Sprinkle sugar over it and put butter in pieces on top. Pour apple juice. Braise in the hot oven for about 25 minutes.
Whip the cream until stiff. Fold in liqueur. Dust apples with icing sugar and serve cream. Vanilla ice cream tastes good with it.