2 oz. Light Rum
.75 oz. Simple Syrup
1 oz. Club Soda
.75 oz. Lime Juice
8 Mint Leaves (plus 1 mint sprig for garnish)
Add the simple syrup and mint leaves to a mixing glass and muddle. Add everything else, then shake and fine-strain into a chilled Collins glass filled with ice. Top with 1 oz. club soda and garnish with the mint sprig.