In a medium saucepan over medium heat, combine butter, brown sugar, and milk. Stir gently until the butter melts and the mixture starts to bubble slightly.

Once the sugar dissolves, remove from heat and mix in peanut butter and vanilla extract until smooth.

Gradually add oats, stirring until they are evenly coated. The mixture should be sticky and hold together when pressed.

Using a tablespoon or small cookie scoop, portion the oat mixture onto a parchment-lined tray.

Flatten each portion slightly into a circular shape with the back of a spoon and create a small indentation in the center of each cookie to hold the caramel.

Spoon about a teaspoon of caramel sauce into the indentation of each cookie.

Ensure the caramel is generously applied, as it will firm up slightly when cooled.

Melt chocolate chips in the microwave in 20-second bursts, stirring after each interval until smooth.

Transfer the melted chocolate to a piping bag or use a spoon to drizzle over the cookies in sweeping lines.

Refrigerate the cookies for at least 30 minutes to allow them to firm up.

This chilling time helps the caramel set and enhances the overall texture.