Black Cow Caramel Sauce

Yield: 1 1/2 cups. Boil root beer in a heavy medium saucepan until it is reduced to 2/3 cup, 12 to 15 minutes. Remove from pan and set aside. Pour the sugar into the same pan. Drizzle water over so all over sugar is moistened. Cook over high heat, swirling pan often, until mixture turns a rich amber color, 7 to 10 minutes. Remove from heat and add butter. When it melts, stir it in and add the cream and reduced root beer. Return to high heat and heat to a boil. Whisk vigorously. Serve hot or cold.