In a small glass bowl mix the sugar, corn starch, cocoa, and salt. Add ¾ cup of the milk, mix, microwave for 1 minute, and mix some more.

Pour the mixture into a 4 cup Pyrex Measuring Cup and add the remaining (2 cups) of milk. Whisk.

Repeat the following until the mixture boils (8 minutes total for me):

1. Microwave on high for 2 minutes
2. Whisk

Reduce heat and boil for 1 more minute.

Cut four pieces of plastic wrap to cover the cups.

Stir in the butter, vanilla, and cinnamon.

Pour into 4 cups; cover with plastic wrap.