In medium saucepan, stir together sugar, cocoa and salt. Gradually add water, stirring to keep mixture smooth. Cook over medium heat, stirring constantly, until mixture boils; boil and stir 3 minutes. Remove from heat; stir in vanilla.
Pour into heatproof container. Cool to room temperature. Cover; refrigerate. Use as topping for ice cream and desserts or for chocolate-flavored drinks. About 2 cups syrup.
HOT COCOA: Add 1 to 2 tablespoons COCOA SYRUP to mug of hot milk; stir until blended.
COCOA SYRUP DRINK: Add 1 to 2 tablespoons COCOA SYRUP to tall glass of cold milk; stir until blended.