1 oz of Light Rum
2 tbsp of white creme de cacao (or chocolate liqueur)
1 tsp of cream
1 1/2 oz of blue curacao liqueur
Pour the rum, blue curacao, creme de cacao and cream into a cocktail shaker half-filled with cracked ice. Shake well. Strain into an old-fashioned glass 1/4 filled with ice cubes, and serve.