When espresso is still hot, stir in sugar. Chill espresso in fridge until completely cold. This will immensely speed up the time it takes to freeze. Once cold, pour into a large, wide baking dish; I’d recommend something ceramic, glass, or enameled over a metal-surfaced baking pan. If you’re me, clear your horribly overstuffed freezer of things that can survive outside of it for a few hours. Place dish in now-cleared freezer and freeze for one hour, then remove the mixture and scrape with two forks to break up the ice. (Your freezing time will vary, depending on the temperature and muscle of your freezer.) Return to the freezer and freeze until solid, about 2 to 3 hours, scraping it again with forks every 30 minutes or so. To serve, whip cream to soft peaks; estimate 2 tablespoons unwhipped cream per serving so you don’t have to make too much at a time. Place one spoonful in the bottom of a small glass. Scoop granita on top. Top with a much larger tuft of cream. Eat with a spoon on a hot day.