- Slightly brown margarine in heavy saucepan.
- Stir in sugar, salt, vinegar, corn syrup, and milk.
- Cook over medium heat in covered pan until boiling.
- Add cocoa and increase heat to high.
- Cook until soft ball stage (238 degree F), stirringly only when necessary.
- Remove from heat and cool to lukewarm.
- Add vanilla extract and beat vigorously until candy thickens.
- Stir in chopped nuts, and pour onto a lightly buttered platter.
- Serve immediately.