Combine all ingredients in an 8-inch 20 cm square non-metal pan; stir until sugar is dissolved. Cover and freeze 6 hours or overnight. To serve, scrape a fork over the surface of the frozen mixture and spoon a heaping cup 250 mL into a 10 oz 300 mL glass. Add a little more cranberry cocktail and stir to form slush. Makes 6 servings.
