Step 1

Line a baking sheet with wax paper or parchment paper and set aside.

Step 2

In a medium saucepan, combine butter, sugar, milk, and cocoa powder. Over medium heat, bring the mixture to a boil. Allow it to boil for 1 minute, stirring frequently.

Step 3

After 1 minute, remove the saucepan from heat. Stir in the peanut butter and vanilla extract until well combined and the peanut butter has melted.

Step 4

Add in the oats, stirring until all of the oats are coated with the mixture and everything is well combined.

Step 5

Drop spoonfuls of the mixture onto the prepared baking sheet. You can make them as large or as small as you prefer. Flatten the cookies slightly with the back of your spoon if you prefer a less "domed" cookie.

Step 6

Let the cookies sit at room temperature until cooled and hardened, about 30 minutes.

Step 7

Once the cookies have hardened, they can be served. Store any leftovers in an airtight container at room temperature.