Preparation Pour 4 cups root beer into 13x9x2-inch baking pan; freeze until set, about 4 hours or overnight. Meanwhile, boil remaining 4 cups root beer in large saucepan until reduced to 1/2 cup, about 30 minutes. Cool root beer syrup. Using tines of fork, scrape frozen root beer into icy flakes, then mix gently in pan to blend. Spoon 3/4 cup root beer granita into each of 6 clear glasses or dessert cups. Top granita with scoop of ice cream. Drizzle each with 4 teaspoons root beer syrup and serve.
Preparation Pour 4 cups root beer into 13x9x2-inch baking pan; freeze until set, about 4 hours or overnight. Meanwhile, boil remaining 4 cups root beer in large saucepan until reduced to 1/2 cup, about 30 minutes. Cool root beer syrup. Using tines of fork, scrape frozen root beer into icy flakes, then mix gently in pan to blend. Spoon 3/4 cup root beer granita into each of 6 clear glasses or dessert cups. Top granita with scoop of ice cream. Drizzle each with 4 teaspoons root beer syrup and serve.