Make your simple syrup by combining 1 cup sugar and 1 cup water in a small saucepan over medium high heat and stirring until sugar is completely dissolved. Allow it to cool.
When ready to make the drink, start by place ice in a large shaker.
Add simple syrup, cranberry juice and lime juice. Shake to combine.
Divide mint leaves and sugar between 2 glasses and muddle to bruise leaves and grind sugar.
Add ice to the glass. Pour the mocktail mixture over the ice.
Top off the glass with club soda.