Prepare a level surface with two sheets of parchment paper or silicone baking mats.

In a 3-quart heavy-bottomed saucepan, combine butter, granulated sugar, milk, and cocoa powder.

Apply medium-high heat and whisk constantly until the butter is liquefied and ingredients are homogenized.

Bring the mixture to a full rolling boil (surface remains agitated despite stirring) and initiate a timer for exactly 60 seconds.

Immediately remove the saucepan from the heat source to prevent over-crystallization of the sugar.

Stir in the creamy peanut butter, vanilla extract, and salt until the emulsion is smooth and the peanut butter is fully incorporated.

Add the quick-cooking oats and fold until every flake is uniformly coated with the chocolate-peanut butter mixture.

Using a mechanical scoop or two spoons, portion approximately 30ml (2 tablespoons) of the mixture onto the prepared parchment paper, spacing them 5cm apart.

Allow the cookies to cool undisturbed at room temperature (approximately 21°C) for 30 minutes until the matrix has fully set and the cookies can be lifted without deformation.