Mom often made fudge when we were growing up, using a candy thermometer or "a drop of candy in water" method of testing it to see if it was done. I never got the hang of it. But sometimes, she didn't either & we ate the delicious "spoon candy."
Then around 1976, my friend & neighbor, Anita E., showed me how to make this version of no-fail fudge and a new holiday tradition was born in my house, my mother's house, my mother-in-law's house, and many friends' houses.
Prepare a 13 x 9" pan by lining it with aluminum foil, allowing the foil to overlap the top to allow you to pick it up later. Alternately, butter a 13 x 9" pan. (No butter is needed if you use aluminum foil.)
Have everything measured & lined up on the counter. Once the base cooks, everything goes VERY QUICKLY!
Combine sugar, margarine, and evaporated milk in a large heavy saucepan.
STIRRING CONSTANTLY, over medium heat, bring to a full, rolling boil. Continue boiling for 5 minutes (still over medium heat) while stirring.
Remove from heat. Quickly stir in chocolate chips until melted.
Then add the vanilla extract, marshmallow cream, and nuts.
Beat until well-blended. (You have to be quick, but thorough.)
Pour into the prepared 13 x 9" pan and smooth the top. Cool to room temperature. If you used foil to line the pan, you can lift up the candy using the foil edges and place on a flat surface. Smooth out the foil.
Cut the fudge into squares. Store in airtight containers. Makes 3 pounds of fudge.