This tastes so good you’ll be making extra coffee just to have leftovers! Basically it’s sweetened coffee with milk or half-and-half frozen. The trick is to keep stirring it while it freezes so you don’t end up with one big chunk of frozen coffee.
Feel free to adjust the proportions. This was just about right to fill an 8×8 baking pan.
4 cups cold coffee
1 cup sugar
1 cup cream, half-and-half, or milk
Stir until the sugar is dissolved (or add it while the coffee is still warm and then chill). Pour the chilled coffee mixture into a pan that can go in your freezer. Set the timer for 30 minutes or so and stir the mixture. Keep setting your timer and stirring until it’s frozen but broken up into small shard-like pieces. If you have leftovers, they’ll freeze solid but you can scrape them with a fork to break them up again into pieces.
Edited to add: How long this takes depends on how deep the granita is, how cold the coffee is when you start and how cold your freezer is. Allow 2-3 hours in the 8×8 dish I used, but if you poured it into two containers so it was shallower it will freeze faster and be easier to stir.0