Squeeze the lime into a cocktail shaker and add the mint leaves. Muddle together using a muddler or the end of a wooden spoon. Add the Bacardi, sugar and a handful of ice. Place lid on shaker and shake away.
Strain the mixture into a glass (martini glass suggested). Top each cocktail off with a splash of club soda and a drizzle of Creme de Menthe (which will sink to the bottom). Add a lime wedge for garnish, and serve.