Grease a 9x13 pan or use parchment paper to line.Gather and pre-measure all ingredients and have ready.
In a heavy-bottomed saucepan (about 3qt), combine the butter, sugar, evaporated milk and bring the mixture to a boil over medium heat. Once it begins boiling, start timer and continue to cook for 5 minutes, stirring constantly.
Remove the pan from the heat and quickly stir in the chocolate chips, marshmallow creme, vanilla, and nuts if using. Beat the mixture until everything is well blended and smooth. Moving quickly.
Pour the fudge into a greased 9x13-inch pan, spreading it evenly. Allow it to cool completely at room temperature, then cut into squares. Store the fudge in an airtight container at room temperature. This recipe yields about 36 (2x2-inch) squares.
Notes
Once the fudge starts to boil, begin the timer. Cooking for to long will yield a dry fudge.