2 cups strong coffee (leftover is fine, make sure it's strong)
1/3 cup sugar
Whipped cream, from a can
Combine the coffee and sugar in a bowl and mix until the sugar dissolves.
Transfer the mixture to an 8-inch x 8-inch baking dish. Place the dish in the freezer and freeze until ice granules start to form around the edges. Scrape the ice with a fork. Do this every 20 minutes or so until the mixture becomes an icy slush.
Serve in 4 ounce glasses topped with whipped cream.