2 oz of Dark rum
1 oz of creme de cacao (or chocolate liqueur)
1/2 oz of double cream (or whipped cream)
1/2 oz of grated nutmeg (or nutmeg)
Pour the dark rum into a cocktail shaker half-filled with ice cubes. Add the creme de cacao and double cream. Shake well and strain into a chilled cocktail glass. Sprinkle with grated nutmeg on top, and serve.