In a saucepan, combine sugar, cocoa and salt. Add water; bring to a boil. Cook and stir for 2 minutes. Stir in milk; heat to serving temperature (do not boil). Remove from the heat; stir in vanilla. Whisk until frothy. If desired, garnish with marshmallows, cream or cinnamon sticks.
For Swiss Mocha Cocoa: Add 2 to 2-1/2 teaspoons instant coffee with vanilla. For Canadian Cocoa: Add 1/2 teaspoon imitation maple flavoring with vanilla. For Slim-Trim Cocoa: Omit sugar. Combine cocoa, salt and water. Substitute fat-free milk. Proceed as above. Stir in vanilla with artificial sweetener equivalent to 1/2 cup sugar.