Place the ice, Cointreau, rum, and pomegranate syrup into a blender, blend until smooth. Moisten the rim of a tumbler with the cut edge of the orange slice, and dip the glass into the sugar to line the rim. Pour the granita into the glass, and garnish with the orange slice to serve.
Ingredients
2 teaspoons white sugar
1 cup ice
1 orange slice
1 (1.5 fluid ounce) jigger Cointreau or other orange liqueur