In a small saucepan, combine sugar, water, and cinnamon stick. Bring to a boil, then simmer until the sugar has completely dissolved into a clear syrup. Remove from heat and discard the cinnamon stick. Allow to cool.

In a medium metal bowl, whisk together the cooled sugar syrup, red wine, and orange zest.

In a clean bowl, beat the egg whites until soft peaks form. Gently fold into the red wine. Cover and place in the freezer. Whisk the mixture about every hour for three hours to break up the ice crystals and keep the mixture fully combined. Allow to continue to freeze until desired texture.

Before serving, whisk one more time. Serve in chilled glasses immediately garnished with mint leaves.