Preheat oven to 350°F (177°C). Line a large cookie sheet with parchment paper or a silicone baking mat.
Add peanut butter and cocoa powder to a large mixing bowl. Mix until the cocoa powder is fully incorporated and the mixture is uniform in color.
Sift in the powdered sugar. I recommend sifting it in because powdered sugar tends to get a little clumpy and you will not be able to break up the clumps once they are in the dough. Stir the powdered sugar into the dough until it is completely incorporated and a thick dough forms. You can taste the dough at this point and if you wish for more sweetness you can add another 1-2 tbsp of powdered sugar. If you want more chocolate flavor you can add another ½ to 1 tbsp of cocoa powder.
Using a 2 tsp cookie scoop, scoop the dough and release onto the prepared cookie sheet, spacing dough balls one inch apart.
Using your fingertips, lightly smooth just the surface of the cookie balls, but be careful not to flatten them.
Place cookies in the oven and bake for about 11-12 minutes. The cookies won't change much in size, but they should look dry and baked rather than still wet dough. Let cookies cool completely and set before removing them from the cookie sheet. Dust with powdered sugar before serving.
