In medium saucepan, mix dry ingredients, gradually add water, then mix until smooth.

Carefully bring to boil over medium heat. Reduce heat. Simmer for 2 min.

Add milk. Turn heat to medium and heat just until scalding--do not boil.

Add vanilla and whip with whisk or beater to develop froth and prevent "skin" formation.

Serve immediately.

Adjust cocoa and sugar to preference, bit by bit.