In a large pot, whisk milk, butter, sugar, and cocoa powder. Bring to a boil over medium-high heat. Once mixture comes to a boil, set a timer for one minute.
Remove from heat and add peanut butter, vanilla, then the oats. Mix well.
Place dough by the spoonful on parchment paper or aluminum foil and allow to set for 25-30 minutes. Enjoy!