"My mother in law gave me this recipe several years ago after serving at our Thanksgiving dinner party, and I've been making this traditionally since. With a festive presentation of red cranberry slush afloat of sparkling ginger ale, this is an ideal drink for any festive holiday occasion."
Sprinkle the gelatin over 2 tablespoons cold water and set aside.
Combine the cranberries and 2 cups water in a saucepan over medium-high heat, bring to a boil and cook until cranberries burst. Remove from heat and stir in sugar until dissolved; mix the softened gelatin into the hot cranberry mixture. Pour the cranberries into a shallow freezer-proof container and chill until cold.
When cooled, mix in 2 cups ginger ale and place the mixture into the freezer. Freeze until slushy, about 4 hours. Stir twice during the freezing process to break up the ice crystals.
To serve, fill clear glasses 3/4 full with chilled ginger ale, and spoon some of the cranberry ice overtop. Serve immediately.