1
: In a heavy saucepan, combine evaporated milk, coffee, chopped chocolate, sugar and cinnamon. Bring gradually to a simmer over medium heat, stirring with whisk to melt chocolate, until mixture is steaming.
2
: Remove from heat. Stir in vanilla. Froth chocolate using an immersion blender or very carefully, process in batches in blender with lid securely on. Serve in mugs, sprinkled with cinnamon or cocoa.