Stir together sugar, cocoa and salt in a 4- to 6-quart saucepan. Heat milk
in microwave until hot, but not boiling; gradually add to cocoa mixture,
stirring until well-blended. Stir in vanilla. Serve immediately or keep
warm over very low heat for up to 2 hours. At serving time, stir; pour into
mugs. Garnish with whipped cream; sift cocoa over whipped cream if desired.
Serves 12.