DirectionsStir together coffee and sugar in a bowl until sugar is dissolved, then stir in vanilla.
Pour into an 8-inch metal baking pan (1-quart capacity) and freeze, stirring every 30 minutes, until slushy, about 1 1/2 hours.
Transfer mixture to a bowl and stir vigorously with a fork until slightly smoother and more uniform in texture, 30 seconds.
Freeze until firm enough to scoop, about 30 minutes more.
Divide granita among serving dishes and top with whipped cream.