Beat the butter and icing sugar in a planetary beater.
Gradually add the whole eggs and the whites, a little at a time.
Sieve in the flour and baking powder.
Drizzle in the milk, add the Demetra creamed chestnuts and the rum.
Use an icing bag to half fill half-circle silicone moulds with the cake mixture.
Place the still-frozen chestnut filling on top and continue filling until three-quarters full.
Bake at 200°C for about 15 minutes, then turn up to 170°C for about 12 more minutes.
Turn out of the moulds and arrange on the plate. Decorate.