If you aren't a fan of spicy, cut back the chiles by 1.
Makes 8 cups
You'll need a slow cooker with a capacity of at least 5 litre.
Serve with biscotti, for dunking.
MAKE AHEAD: The chocolate takes 3 hours to cook, and can be made a day in advance and reheated on LOW or WARM.
8 cups whole milk
3 whole dried guajillo chilli (see headnote)
One 7cm cinnamon stick
2 1/2 cups semisweet or bittersweet chocolate chunks.
1/2 teaspoon ground cayenne pepper
Combine the milk, guajillo chilli and cinnamon stick in the slow cooker. Cover and cook on HIGH for 2 hours.
Uncover and whisk in the chocolate and cayenne pepper, until the chocolate has melted. Cover and cook on HIGH for 1 hour; the sipping chocolate will be quite thick.
Discard the cinnamon stick and the chilli, if desired. Whisk well before serving.
Adapted from "The Chef and the Slow Cooker,".