2/3 c. Hershey's cocoa
3 c. sugar
1 1/2 c. milk
1/4 c. butter
1/8 tsp. salt
1 tsp. vanilla

Thoroughly combine dry ingredients in a heavy 4-quart saucepan. Stir in milk. Bring to a bubbly boil on medium heat, stirring constantly. Then boil without stirring to 234°F (soft-ball stage). Bulk of candy thermometer should not rest on bottom of saucepan. Remove from heat. Add butter and vanilla. Do not stir. Cool at room temperature to 110°F. Beat until fudge thickens and loses some of its gloss. Quickly spread in a lightly buttered 8 or 9-inch pan. Cool and cut in squares.