Instructions:

1. In a medium saucepan over medium heat, whisk together the milk, heavy cream, sugar, cocoa powder, cinnamon, and nutmeg. Heat until steaming but not boiling.
2. In a separate bowl, whisk the egg yolks until smooth.
3. Slowly ladle about 1/2 cup of the warm milk mixture into the yolks while whisking constantly to temper them.
4. Pour the tempered yolks back into the saucepan and continue cooking over medium-low heat, stirring constantly, until the mixture thickens enough to coat the back of a spoon. Do not let it boil.
5. Remove from heat and stir in the melted chocolate and vanilla extract until smooth and fully combined.
6. Strain through a fine mesh sieve for extra smoothness if desired.
7. Refrigerate for at least 2 hours until chilled.
8. Serve in festive glasses topped with whipped cream and chocolate shavings.
9. Keep refrigerated and consume within 2 days.