DIRECTIONS In a medium sized microwavable bowl or 1-quart glass measure, combine sugar, cocoa, and cornstarch. Whisk in milk. Microwave mixture at high for 1 1/2 minutes. Whisk again. Microwave again at medium high, until the mixture thickens (2 minutes). Microwave power differs greatly from one oven to another, so be patient and keep microwaving until you notice the pudding thicken. If you can see into your microwave, you will witness the dark chocolate bubbling under. That's when the pudding thickens. Whisk in the vanilla extract.