Start to finish: 30 minutes, plus chilling
Four 12-ounce cans cola soda (6 cans are needed if making granita)
12-ounce bag frozen cherries, thawed
Chopped maraschino cherries, to garnish
In a large saucepan over high heat, bring the cola to a boil. Use caution and stir regularly until the foam subsides. Boil until you reduce the mixture to 1 cup, about 20 minutes.
In a blender, puree the cherries until smooth. Stir the cherries into the reduced cola and cook for another 2 minutes. Strain the mixture through a fine mesh strainer, discarding any solids. Allow the mixture to cool completely. Refrigerate until ready to use.
To use with shaved ice, drizzle a bit of the syrup over a cone or bowl of ice, then garnish with chopped maraschino cherries.
Alternatively, to make granita, stir 2 more 12-ounce cans of cola into the entire batch of cooled syrup. Pour into a 9-by-13-inch pan and freeze. Every 20 minutes, use a fork to scrape and stir the mixture until it is firm with small ice crystals. Spoon into dishes and garnish with chopped maraschino cherries.