Bring butter, sugar and cream to the boil and simmer for 3 minutes. Add the liqueur and the orange peel. Serve hot on ice cream.

Cut the vanilla pod in halves and take the inside out with a knife. Bring the milk to the boil with the outside and inside of the vanilla pod and simmer for 15 minutes. Whisk the egg yolks with the sugar and slowly add the hot milk. Heat this mixture on very low heat while stirring all the time, until the sauce thickens. be careful that it does not boil! Allow the sauce to cool down.