Mix together in a sauce pan:
2 cups of sugar
1/3 cup of cocoa
1 can of evaporated milk
Bring to a slow boil, as mixture starts to thicken stir often to keep from burning.
1/2 cube of butter
Stir until butter melts and bring back to a slow boil until mixture gets a little thicker. Take off heat and let stand until cool enough to eat.
Store in an air tight container and it will reheat in micro several more times before it goes sugary.