In two tall cocktail glasses, divide the mint leaves evenly. (About 10 per glass)
Place two teaspoons of sugar in each glass and use a muddler to smash the mint leaves with the sugar about 5 times.
Add 2 teaspoons of lime juice in each glass.
Pour 2 ounces of cranberry syrup in each glass, adding a few smashed berries if desired.
Add 2 ounces of white rum to each glass.
Fill each glass to the top with ice and top with club soda.
Garnish with additional fresh or smashed cranberries, fresh lime and mint sprigs.
Serve with a straw or stir stick so your guests can stir before enjoying.