Preheat the oven to 350°F (175°C).
In a mixing bowl, whisk together flour, baking soda, and salt.
In another bowl, cream together softened butter, brown sugar, and granulated sugar until fluffy.
Add the egg and vanilla, mixing until well combined.
Add peanut butter, mixing until smooth and well combined.
Gradually add the dry ingredients to the wet mixture, stirring until just combined.
In a separate bowl, beat the cream cheese and powdered sugar until smooth.
Fold in mini chocolate chips and chopped Reese’s cups into the cookie dough.
Scoop a tablespoon of cookie dough onto a baking sheet lined with parchment paper, making slight indents in the center.
Spoon a dollop of cream cheese mixture into the indents of the cookie dough.
Cover with a bit more cookie dough on top, sealing the filling inside.
Bake for 12-15 minutes, or until edges are lightly golden.
Let the cookies cool on the baking sheet for a few minutes before transferring to wire racks to cool completely.