In medium saucepan, stir together sugar, cocoa and salt; stir in water. Cook over medium heat, stirring constantly, until mixture comes to a boil.
Boil and stir 2 minutes. Add milk; stirring constantly, heat to serving temperature. Do Not Boil. Remove from heat; add vanilla.
Beat with rotary beater or whisk until foamy. Serve topped with marshmallows or whipped cream, if desired. Five 8-oz. servings.
VARIATIONS: Add one of the following with the vanilla extract:
SPICED COCOA: 1/8 teaspoon ground cinnamon and 1/8 teaspoon ground nutmeg. Serve with cinnamon stick, if desired.
MINT COCOA: 1/2 teaspoon mint extract OR 3 tablespoons crushed hard peppermint candy OR 2 to 3 tablespoons white creme de menthe. Serve with peppermint candy stick, if desired.
CITRUS COCOA: 1/2 teaspoon orange extract OR 2 to 3 tablespoons orange liqueur.
SWISS MOCHA: 2 to 2-1/2 teaspoons powdered instant coffee.
COCOA AU LAIT: Omit whipped cream. Spoon 2 tablespoons softened vanilla ice cream on top of each cup cocoa at serving time.
SLIM-TRIM COCOA: Omit sugar. Combine cocoa, salt and water; substitute nonfat milk. Proceed as above. With vanilla, stir in sugar substitute with sweetening equivalence of 1/2 cup sugar.
CANADIAN COCOA: 1/2 teaspoon maple extract.
MICROWAVE SINGLE SERVING: In microwave-safe cup or mug, combine 1 heaping teaspoon HERSHEY'S Cocoa, 2 heaping teaspoons sugar and dash salt. Add 2 teaspoons cold milk; stir until smooth. Fill cup with milk. Microwave at HIGH (100%) 1 to 1-1/2 minutes or until hot. Stir to blend; serve.