1 oz dark Jamaican rum
1 oz light rum (Martinique rhum agricole vieux)
1 oz fresh lime juice (spent lime half reserved)
1/2 oz orange Curacao
1/4 oz orgeat syrup
1/4 oz simple syrup
1 sprig mint, or maraschino cherry (for garnish)
Fill a cocktail shaker with ice.
Add dark rum, light rum, lime juice, Curaçao, orgeat, and simple syrup.
Shake well, then strain into an ice-filled Old-Fashioned glass and garnish with lime rind and a sprig of mint.