Place milk, butter, sugar, cocoa and vanilla in pot. Stir cook on medium/medium high. This really depends on your oven.
This is KEY — when it comes to a boil set your timer to 3 minutes.
This is the other KEY thing – stir the whole 3 minutes preferably with a wooden spoon.
Make sure to have the peanut butter and oatmeal already to stir in when the 3 minutes are done. I make my daughter stir while I get the peanut butter and oatmeal measured out. (If you double the recipe cook for 5 minutes)
Remove from stovetop and add the oatmeal and peanut butter
Drop on wax paper with a spoon
Let sit for 20 minutes