Preheat the oven to 350°F (175°C) and line two cookie sheets with parchment paper.

In a large bowl, whisk together flour, baking soda, and salt until combined.

In another bowl, use an electric mixer to cream together melted butter, brown sugar, granulated sugar, and peanut butter until fluffy. Add vanilla extract and eggs one at a time, mixing well after each addition.

Gradually add the dry mixture to the wet ingredients until just combined. Fold in mini chocolate chips.

Scoop dough onto prepared sheets (about 2 tablespoons per cookie) and space them apart.

Bake for 13-15 minutes until lightly golden around the edges.

Immediately press a Reese's Peanut Butter Cup into each warm cookie and let cool on the pan for five minutes before transferring to a cooling rack.