3tablespoonspowdered sugar plus more for dusting the finished cream puffs
Preheat the oven to 425 degrees. Line a baking sheet with parchment paper or a silicone baking mat.
Combine the flour, cocoa powder, and sugar in a small bowl and whisk well.
Combine the water, butter, and salt in a heavy medium saucepan over medium-high heat. Bring to a simmer and continue to cook until the butter is melted. Add the flour mixture all at once and stir with a wooden spoon until it forms a thick dough. Continue cooking and stirring for 1 more minute.
Dump the dough into the bowl of an electric mixer, preferably fitted with a paddle attachment. Mix on low speed for 30 seconds to cool the dough slightly. Add the eggs, one at a time, mixing very well after each addition. After all the eggs have been incorporated, continue to beat, increasing the speed to medium-high, until the dough is smooth, thick, and shiny, about 2 or 3 minutes.
Pipe the dough onto the prepared baking sheet into 6 (2-3 inch) mounds (or you can make smaller ones) or use an ice cream scoop to scoop out the batter, spacing about 1 inch apart. To pipe, you can scoop the mixture into a large food storage bag, snip about ½ inch off one of the corners, and squeeze the mixture out onto the baking sheet. Moisten your finger with water and press the peaks down so they don’t burn.
Bake for 10 minutes, reduce the oven temperature to 350, and cook for another 30 minutes or so, depending on the size, or until the dough has risen and puffed and the puffs sound hollow when tapped on the bottom. Turn off the oven and leave the puffs in the oven for 20 minutes. Remove from the oven and pierce the side or bottom of each puff with a sharp knife to let the steam escape. Let cool on a wire rack. These can be made ahead by as much as a month and stored in the freezer, if wrapped airtight. Thaw at room temperature before filling.
Make the cream filling by combining the cream, peanut butter, and powdered sugar in a mixing bowl fitted with the whisk attachment. Whip on high speed until stiff but not dry.
Cut the puffs in half and fill with the peanut butter whipped cream. Dust the tops with powdered sugar and serve.