Instructions
1. Combine cocoa, sugar, salt, and heavy cream in a large saucepan. Bring to a rolling boil; then reduce heat to medium and cook to 234°F with out stirring.
2. Remove from heat and add butter and vanilla. Do not stir.
3. Cool to lukewarm (about 110°F).
4. Beat by hand or with mixer until fudge thickens and loses some of its gloss.
5. Quickly spread fudge in lightly buttered, parchment-lined, 8-inch square pan.
6. When cool, cut into squares.
