Debbie Snarr's Fantasy Fudge

3/4 c. (1 1/2 cubes) butter or margarine
3 c. sugar
2/3 c. (5 oz can) evaporated milk
2 c. (12 oz. pkg.) semi-sweet chocolate chips
1 jar (7 oz.) Jet-puffed marshmallow creme
1 tsp. vanilla
1 c. chopped nuts (optional)

Mix melted margarine, sugar, and milk in heavy 2 1/2 to 3-quart saucepan; bring to full rolling boil on medium heat, stirring constantly. (Don't scrape the sides of the pan as you stir.) Continue boiling for 5 minutes or so on medium heat or until candy thermometer reaches 234 F, stirring constantly to prevent scorching. Remove from heat. Being careful not to scrape the sides of the pan, stir in chips until melted. Add remaining ingredients; mix well. Pour into a buttered pan. Cool at room temperature; cut into squares.

(Tip: Do not scrape the sides of the pan as you pour it-- it will make the fudge crystally, instead of creamy. Scraping the bottom is okay, but for the sides, turn the spoon over to sort of "push" it out. There will be a lot left in the pan, but the creamy fudge is worth it! After the fudge is poured, scrape the sides into the bowl and eat as "samples.")

Rocky Road Fudge: After all the other ingredients are mixed together, stir in chopped walnuts & mini marshmallows--as many of each as you like. Then carefully pour into the buttered pan.