Soak the gelatine in cold water. Mix the yolks with sugar until creamy. Bring the milk with gingerbread spices and a small pinch of salt to the boil and pour into the yolk mixture, stirring constantly. Empty the mixture into the saucepan and keep stirring over low heat until creamy. Pour the cream into a bowl and let cool down a little. Squeeze out the gelatine well and dissolve it in the still warm cream. Stir in rum. Whip the cream. Mix a third of it with the cream, fold in the rest. Cover the bowl with cling film and put the cream in a cool place.