2 cups lukewarm extra strong coffee or espresso
1/2 c sugar
2 T coffee liqueur (optional)
1 t lemon or orange zest
dissolve sugar in coffee. add liqueur and zest. place in 9x13" baking dish on level surface of freezer. every 30 mins or so, with a dinner fork, scrape newly formed ice from the sides of the dish into the middle, being sure to break up any large chunks.
after about 3-4 hrs, scrape surface of granita with fork, and spoon into a large, airtight container. sput back in freezer for 2 more hours.
scrape granita into bowl and top with barely sweetened whipped cream.