1. In a saucepan simmer the milk, sugar and vanilla bean for 30 minutes. Remove from heat, and allow to cool.
2. In a bowl beat the yolks until light lemon color. When the milk mixture is cooled, remove the vanilla bean. Beat in the egg yolks. Return to the heat and bring just to boiling point.
3. Remove from the heat immediately, do not allow to boil. Cool again and add the rum. Bottle and refrigerate. Use after 2 days. Serve as an after-dinner drink, or as a dessert with fruits.