Hershey's Classic Rich Cocoa Fudge

Hershey's Classic Rich Cocoa Fudge:
YIELD: 36 squares

3 C sugar
2/3 C unsweetened cocoa (Hershey's)
1/8 tsp. salt
1 1/2 C milk
1/4 C butter (half stick)
1 tsp. vanilla extract

Line and 8 or 9 inch square pan with aluminum foil, butter the foil. Mix sugar, cocoa, and salt in a 4qt. saucepan, add milk. Cook over medium heat, stirring constantly until mixture comes to a full boil. Boil without stirring until mixture reaches 234* on a candy thermometer or soft ball stage. Remove from heat, add butter and vanilla, do not stir. Cool at room temp. to 110* Beat with a wooden spoon until fudge begins to thicken and loses its gloss. Spread quickly into pan, let cool to room temp., cut into squares.