Combine sugar, cocoa, salt and hot water in 1-quart micro-proof measuring cup (or coffee mug).
Microwave at HIGH (100%) for 1 to 1 1/2 minutes or until boiling.
Add milk, sitr and microwave an additonal 1 1/2 to 2 minutes or until hot.
Stir in vanilla, blend well.
Serve: Coffee mug