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. Variations: 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.