Never Fail Fudge

2 1/2 cups sugar
1/2 teaspoon salt
1/2 stick of butter
1 5ounce can evaporated milk (2/3 cup)
1 Jar (7 1/2 ounce) Marshmallow Fluff
3/4 teaspoon vanilla
1 12 ounce package semi-sweet chocolate pieces

1/2 cup chopped walnuts (optional)

Grease a 9-inch square baking pan; set aside. In a large saucepan combine the first five ingredients. Stir over low heat until blended. Increase the heat to medium and bring to a full-rolling boil being careful not to mistake escaping air bubbles for boiling. Boil slowly, stirring constantly for 5 minutes.
 (use Soft-Ball test)
http://www.marshmallowfluff.com/pages/faq.html#Anchor-What-47857).
 Remove from heat, stir in vanilla and chocolate until chocolate is melted. Add nuts. Turn into greased pan and cool. Makes 2 1/2 pounds.

Hint: As with all fudge recipes, cooking time will vary depending on factors such as humidity and altitude. For best results, use the softball test to make sure the fudge has been cooked enough.