A bartender's nightmare because it involves cream. Take a large brandy, mix it with creme de cacao and double cream (one part cacao, one part cream and two parts brandy) and shake the whole thing over ice. Strain into glass and top with grated nutmeg or chocolate. Curiously popular with old ladies but not as nice as a Grasshopper.
"Can I have three Brandy Alexanders please?" - order guaranteed to piss off this bartender.