1 oz of white rum (or Light Rum)
1/2 oz of rosso vermouth (or sweet vermouth)
1 tsp of Lime Juice
1/2 oz of grand marnier orange liqueur (or orange liqueur)
2 oz of chilled cola (or coke)
Pour into an old-fashioned glass half-filled with broken ice. Garnish with a twist of lime, and serve.