Start off by making the filling. Grab a bowl and combine the peanut butter and powdered sugar and mix together until well combined.
1/2 cup peanut butter, 1/2 cup powdered sugar
Taking 1-2 tsp sizes, roll the filling into balls using your hands (your hands are the best tool in the kitchen;) The warmth from your hands will help form the balls easy!
Place in the refrigerator while you start on the cookie dough.
In a stand mixer, cream together butter and sugars. Ideal creaming time is 3-5 minutes on medium speed, scraping the bowl every now and then with a spatula.
1/2 cup brown sugar, 3/4 cups butter, 1/3 cup white sugar
Add in egg and vanilla and continue mixing.
2 tsp vanilla, 1 egg
Take the flour, cocoa powder, and baking soda, and add into the mixing bowl. Mix on a low speed until a thick dough forms.
1 + 1/3 cups flour, 1/2 cup cocoa powder, 1/2 tsp baking soda
Scoop out about 1 tbsp of dough onto your prepared baking sheet. Press it down firmly and add one of the peanut butter balls that was made previously on top of each cookie. Top off with additional cookie dough and 'close' the cookie (See step-by-step photos or video above).
Place into refrigerator to chill for 30 minutes. Once chilled, bake at 350°F for 12-14 minutes. Top off with dark chocolate chips if wanted.
1/2 cup dark chocolate chips
Enjoy!