Scrape out the vanilla pod. Bring all the ingredients to the boil in a large saucepan. Simmer over a very mild heat for about 70 - 80 minutes, stirring again and again. After about 30 minutes, remove the vanilla pod and cinnamon sticks. When the mixture has boiled down until it is viscous, the cream is ready. Fill into glasses while still hot.
The finished cream can be kept for about 5 to 6 months.