2 cups sugar
1 can (5 ounce size) evaporated milk
1/3 cup milk
1/8 teaspoon salt
1/4 cup butter
1 teaspoon vanilla extract
broken nuts (optional)
Line an 8x4x2-inch loaf pan or 8×8 pan with foil, extending foil over edges of pan. Butter foil; set aside. Butter the sides of a heavy 2-quart saucepan.
In saucepan combine sugar, evaporated milk, milk, and salt. Cook and stir over medium-high heat to boiling. Carefully clip a candy thermometer to the side of the saucepan. Cook and stir over medium-low-heat to 238 degrees F, soft-ball stage (this should take 25 to 35 minutes). Immediately remove saucepan from heat.
Add butter and vanilla, but do not stir. Cool mixture, without stirring, to 110 degrees F, lukewarm (about 55 minutes).
Remove candy thermometer from saucepan. Beat vigorously with a wooden spoon till fudge becomes very thick and just starts to lose its gloss (about 10 minutes total). Do not over-beat. Immediately spread fudge into the prepared pan.
Score into 1-inch squares while warm. Top each square with a piece of nut, if desired. When candy is firm, use the foil to lift the fudge out of the pan. Cut into squares. Store, tightly covered, in the refrigerator.