Begin by making the peanut butter filling. In a medium size bowl, mix together the peanut butter and powdered sugar until combined. Roll into 12-tablespoon size balls (about ¾ oz or 22 g each). Set aside.
Add the flour, cocoa powder, baking soda, and salt to a bowl and whisk them together.
Use a stand mixer fitted with the paddle attachment or a hand mixer to beat the butter and both sugars together until creamy and pale. Then, mix in the egg and vanilla extract. Beat well to combine.
Add in the dry ingredients and beat until a dough forms.
Use a large cookie scoop to scoop out 12 portions of chocolate cookie dough (about 1 ¾ oz or 50 g). Flatten a chocolate dough ball and add a peanut butter ball to the center. Shape the chocolate dough over the peanut butter filling, covering it completely and roll it into a ball. Continue until all of the cookies are shaped.
Place the shaped cookies onto a lined pan and chill them in the refrigerator for 30 minutes.
While the cookies are chilling, preheat your oven to 350 degrees F. Line baking sheet with parchment paper.
Arrange 4 chilled cookie dough balls onto your prepared baking sheet and gently press down your fingers to slightly flatten the tops. Bake for 12-14 minutes. Repeat with remaining cookies.
Transfer baked cookies to a wire rack. Top warm cookies with chocolate chips and enjoy!