In a saucepan, heat up Sugar, Butter, Salt and Cream until well combined and bring it to a boil; stirring continuously for up to 4 minutes. Remove from heat.
Quickly stir in your Marshmallow Creme and White Chocolate. Whisk in vigorously until it's a smooth consistency.
Pour half of the mixture into a parchment paper lined 13 x 9 dish. With the remaining other half of fudge, whisk in the Root Beer concentrate and stir together. Pour this half over the white fudge. Using a knife, swirl the two together layers together and refrigerate for about 4 hours. Cut into squares and Enjoy your Fudge!! :)