Heat the milk (or a mixture of cream and milk for a richer result) until it simmers and whisk it into the chocolate. Pour into individual cups and serve with rum or whipped cream, if using. Top with chocolate shavings.
In a medium saucepan over low heat, bring the cream, sugar, cinnamon and butter to a rolling boil. Remove from the heat, add the chocolate and stir until the chocolate melts. Add the rum and stir in the orange zest before serving.
*This recipe can be made even more "evil" by substituting 2 cups of cream and mixing it with 4 cups milk.