Put a shallow baking dish or tin into the freezer to chill.

Stir and dissolve the sugar into the coffee over a low heat. Set aside to cool down. Add the coffee liquor, vanilla into the coffee mixture. Taste and adjust the sugar accordingly.

Pour the coffee mixture into the chilled dish and freeze for about 40 minutes or so. Cover the dish with the lid and keep in the freezer. Check to see if there are any ice crystals forming around the edge. If there is, gently bring them into the liquid centre using a fork. Place the granita back into the freezer

Have another look again in about 30 minutes and repeat the same process as step 3. Keep doing this until the entire mixture is a mass of coffee crystals with no remaining liquid parts. Once this has been achieved, tip the granita into a plastic, lidded box and store in the freezer until needed.

Before serving keep the bowls/glasses in the fridge for some time. To serve the granita, stir the frozen mixture with the fork to form coffee crystals.

Serve the granita in pre-chilled glasses with the whipped cream on top.