Preheat your oven to 350 F / 180 C, line your baking tray with parchment paper, and keep aside.
Mix flour, cocoa powder, baking soda, and salt in a large bowl. Keep it aside.
In a stand mixer (you can also use the hand mixer for this) add in the butter, and both the sugars and beat it at medium speed, scraping down the sides for at least 2-3 min or until the mixture is creamy.
Add in the egg along with vanilla extract and beat until everything is incorporated well.
Add the flour mixture to the butter mixture in batches and mix till the dough is formed
Divide the dough into 6 equal parts. You can use a kitchen scale for exact measurements.
To make the cookies, take one part of the cookie dough and flatten it into a disc using your hands. Place a tbsp of peanut butter filling in the center and then fold the edges of the cookie dough up around the peanut butter to form a ball. Roll it a little between your palm to make a smooth ball, flatten it a bit, and place it on the baking tray. Make sure to keep the balls at least 3 inches apart.
Bake for 10-11 min in a preheated oven.
Let the cookies cool for 5 minutes in the baking tray before transferring them to a wire rack to cool completely.
Sprinkle them with some powdered sugar.
Serve and enjoy!!