Place milk, cream, cinnamon sticks, nutmeg, vanilla pod and seeds in a pot. Bring to a light boil and remove from heat.
Mix egg yolks and sugar in a large bowl until pale in color. Slowly pour in the milk mixture while whisking. Cool to room temperature, strain and refrigerate.
Once the mixture is chilled serve with 1 1/2 ounces rum, brandy, or whiskey per cup of eggnog. For a large batch mix 15 ounces of rum with all the eggnog. Garnish with freshly ground nutmeg and serve immediately.