In a large sauce pan over medium heat, melt the butter.
Once melted, add in the sugar, milk, and cocoa powder. Heat and stir until smooth.
Bring to a boil and let boil for about a minute without stirring.
Remove from the heat, add in the peanut butter, and stir until it's melted in.
Add in the vanilla, stir, and add in the oats. Stir to fully coat and combine.
Let the mixture cool for a minute or three, and prep your cookie sheet with parchment paper.
Using a cookie scoop or tablespoon, scoop out balls of dough. Space them out on the cookie sheet and flatten them slightly, in whatever shape you like.
Let the cookies cool and solidify for about an hour, and enjoy!