Line a 9"x13" with foil and spray with non stick cooking spray. Set aside.
In the top of a double boiler, combine 3 cups granulated sugar, 6 tablespoons butter, and ? cup evaporated milk.
Bring the mixture to a rolling boil over medium heat, stirring constantly. Continue boiling for 5 minutes, or until the mixture reaches approximately 212°F on a candy thermometer.
Remove the double boiler from the heat. Stir in 2 cups semi-sweet chocolate chips and 1 (7-ounce) jar marshmallow creme until completely melted and smooth.
Stir in 1 teaspoon vanilla extract until fully incorporated. Fold in 1 cup chopped walnuts, if using.
Pour the fudge mixture into the prepared baking pan and spread it into an even layer. Let the fudge cool completely until set.
Lift the fudge out of the pan using the foil or parchment paper. Cut into 30 squares. Serve and enjoy.
Notes
Remember, the nuts are completely optional. You are going to love this recipe for fudge!