Delicious chocolate fudge sauce so good you will want to eat it with a spoon.
In a sauce pan on medium to medium high heat, mix butter, cocoa, and sugar thoroughly, then add the milk, stirring constantly. Boil for 7 minutes.
Remove from heat and add vanilla.
Blend in a blender for 3-4 minutes. Pour into small jars and store in the refrigerator. Reheat when ready to use.