36.8-ounce Symphony Bars or 20.8-ounces of milk chocolate candy bars, (I like Dove, Symphony or Toblerone Bars)
2sticks of butter
1cupnutschopped and toasted, if desired
Begin by lining a 9x13-inch pan with parchment paper. Next break up chocolate bars into a large heat-proof mixing bowl. Set up electric mixer.
Butter the sides of a large, lidded, heavy, pot. Pour cream and sugar into pot and stir together. Place over medium heat and stir constantly, just until it comes to a rolling boil. When it reaches this point, cover pot with lid for 1 minute and then remove the lid. Continue cooking to a soft ball stage, 230˚degrees on a candy thermometer.
Remove pot from heat, add butter and vanilla. Let it sit in the hot candy mixture for 1 minute without stirring. Pour candy over broken chocolate bars in mixing bowl. Do not scrape the pan. Beat fudge until very smooth with beaters. Add stir-ins, nuts, peanut butter, or candies at this point. Pour into prepared pan, cover and refrigerate till set, preferably overnight.
To cut, using the parchment paper, lift the slab of fudge to a cutting board. Cut with a sharp knife or pizza cutter into even squares. Keep refrigerated in a sealed container.