Directions
Whisk the egg yolks and sugar in a bowl until pale and thick. Combine the milk, 1 cup of heavy cream, nutmeg, cinnamon, and salt in a saucepan over medium heat. Heat until steaming but not boiling. Slowly whisk 1 cup of the hot milk mixture into the egg yolks. Pour the tempered egg mixture back into the saucepan. Cook over medium-low heat, stirring constantly, until the mixture thickens enough to coat the back of a spoon. Do not let it boil. Remove from the heat and stir in the vanilla extract. Cool to room temperature, then refrigerate for at least 3 hours. Whip the remaining heavy cream until soft peaks form and fold it into the chilled eggnog before serving.