Place the milk and brown sugar in a medium saucepan and bring just to a simmer. Off the heat, whisk in the chocolate, vanilla, cinnamon, and cayenne pepper. Allow to steep for 3 minutes. Reheat the mixture over low heat until it almost comes to a simmer.
Pour into mugs, add cinnamon stirrers, if using, and serve with cinnamon doughnuts for dipping.
Copyright 2012, Barefoot Contessa Foolproof by Ina Garten, Clarkson Potter/Publishers, All Rights Reserved