Hershey's Cocoa Fudge

Source: Mimi's Cyber-Kitchen

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

Thoroughly combine cocoa, sugar and salt in a heavy 4 quart saucepan; stir in milk. Bring to rolling boil over medium heat, stirring constantly. Boil without stirring to 234 degrees (soft ball stage) or until a small amount of mixture dropped into very cold water forms a soft ball which flattens on removal from water. (Bulb 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 degrees; beat until fudge thickens and loses some of its gloss. Quickly spread in a lightly buttered 8 or 9 inch square baking pan; cool.

VARIATION:
Marshmallow nut: Increase cocoa to 3/4 cup. Cook fudge as above. Add 1 cup marshmallow creme with butter and vanilla. Do not stir. Cool to 110 degrees. Beat 10 minutes; stir in 1 cup broken nuts and pour into pan. (Fudge does not set until poured into pan.)