In a medium saucepan over medium heat, combine the granulated sugar, cocoa powder, unsalted butter, and milk. Stir until the mixture comes to a boil. Allow it to boil for 1 minute without stirring.

Remove the saucepan from heat and stir in the creamy peanut butter, vanilla extract, and a pinch of salt until smooth and well combined.

Gradually add the quick-cooking oats to the mixture, stirring until fully incorporated.

Drop spoonfuls of the cookie mixture onto a baking sheet lined with parchment paper. Use a cookie scoop or two spoons to form the cookies.

Let the cookies cool at room temperature for about 30 minutes, or until they are set. For quicker results, you can refrigerate them for about 15 minutes.