Mix together root beer and vodka in a large shallow freezer safe container such as a 9×9 or 13×9 baking dish.
Place container in freezer. Every 20-30 minutes, check on mixture and quickly scrape sides and bottom of container where frozen with fork (or spoon) and mix to combine.
Continue scraping bottom and sides of container for several hours or until desired consistency.
Serve in shot glasses or desired serving glasses/bowls. Top with whipped cream, whipped topping, and/or vanilla ice cream.
SNAPPY TIPS: While mixture is in the freezer, try not to open the freezer door except to check on it. Otherwise it will take the granita a lot longer to freeze. Granita can be made ahead and stored in container.SNAPPY SUBSTITUTIONS: Use any Pinnacle vodka and soda flavor for a whole new drink/dessert!