2 1/2 cups whole milk
4 ounces 99% unsweetened chocolate, coarsely chopped
1/3 cup granulated sugar
1 1/2 teaspoons pure vanilla extract
3/4 teaspoon ground cinnamon (optional)
1/8 teaspoon cayenne pepper (optional)

Heat the milk in a medium saucepan over medium heat until it is hot to the touch. Whisk in the chocolate and sugar and continue whisking for 1 to 2 minutes until the sugar has dissolved. Whisk in the vanilla and the cinnamon and cayenne, if using. Reduce the heat to low. The chocolate may be made ahead; it will thicken as it sits.

Serve in demitasse cups or mugs depending on desired portion. Serves
6 to 8.

Note: For a lighter, airy consistency, remove the hot chocolate from the heat and mix with a hand blender on low speed just before serving. Or make ahead and use the frother of an espresso machine to reheat it. Individual servings can also be topped with frothed milk.

This can be made up to 3 days ahead and refrigerated, but if you use the spices, keep in mind their flavor intensifies over time.