Pour 2 cups of whole milk in the heavy bottomed sauce pan, slit open your vanilla bean and scrape out the seeds and add them to the milk, along with the cinnamon stick and the rest of the spices. Heat the milk over a low heat until the milk is hot and steamy and about to boil. You don't want the milk heating process to happen quickly because the milk needs time to soak up all the wonderful flavours.
While the milk is getting infused, separate your egg yolks from the egg whites and reserve the egg whites for a different use or freeze them. Whip your egg yolks with sugar in a medium sized bowl until the mixture is much paler in colour and doubled in volume. When your milk is ready take it off the heat and remove the cinnamon stick.
With your mixer still running, slowly add half of the milk mixture to the egg mixture to temper the eggs, blend well. Tempering should prevent the eggs from curdling in the next step. Then empty the contents into the saucepan with milk and heat through while whisking continuously on low heat. It took mine 2 minutes. Take off the heat, strain through a fine sieve to ensure eggnog is smooth and silky, add single cream to it and chill until cold.