Line your surface. Set out two baking sheets lined with parchment paper or silicone mats. This keeps the cookies from sticking and makes cleanup easy.

Combine the base ingredients. In a medium saucepan, add the butter, sugar, cocoa powder, and milk. Stir over medium heat until the butter melts and the mixture looks smooth.

Bring to a boil. Increase heat slightly and bring the mixture to a rolling boil. Once boiling, set a timer for 60–90 seconds, stirring occasionally. This brief boil is crucial for the cookies to set.

Remove from heat and flavor. Take the pan off the heat. Immediately stir in the peanut butter, vanilla, and salt until completely smooth.

Add oats. Fold in the rolled oats until evenly coated. The mixture should be thick but still scoopable.

Scoop the cookies. Using a spoon or cookie scoop, drop heaping tablespoons onto the prepared sheets, spacing them an inch apart. Flatten slightly with the back of the spoon if you prefer a thinner cookie.

Let them set. Allow the cookies to sit at room temperature for 20–30 minutes, or until firm to the touch. For faster setting, chill them in the fridge for 10–15 minutes.

Serve and enjoy. Once set, enjoy immediately or store for later. They’ll be chewy with a soft fudge center.