Rum guru Ed Hamilton says this recipe should serve as a reference point, to be tweaked according to taste—just as it was by the Caribbean plantation owners who first sipped the fruity concoction.
1 1/2 oz. dark rum
2 oz. seasonal juices (passionfruit, orange, pineapple, etc.)
1/2 oz. lime juice
1/4 oz. simple syrup (1:1)
Tools: shaker, strainer, barspoon
Garnish: float of Demerara rum plus fresh, seasonal fruit
Shake the rum, juices and syrup with ice. Strain into an ice-filled glass and garnish.
From Ed Hamilton, ministryofrum.com