Mix sugar, butter, and evaporated milk in a large saucepan over medium heat. Stir to dissolve sugar.
Bring the mixture to a full boil, stirring constantly for 4 minutes.
Remove pan from heat and stir in chocolate chips. Continue stirring until they are completely melted.
Add marshmallow creme, vanilla and nuts (if desired.)
Spread into parchment covered pan and let fudge cool.
Remove parchment from pan onto a flat surface, then cut fudge into small squares to serve.
You can leave out the chopped pecans if you want, or substitute them for your favorite nuts. Peanuts, walnuts or cashews work great in this recipe. You do NOT need a candy thermometer to make this Marshmallow Cream Fudge.