Preheat your oven to 350°F. Line a large rimmed baking sheet with parchment and set it aside.
In a large, microwave-safe bowl, place the peanut butter.
If the peanut butter seems very thick and difficult to stir, heat it in the microwave for 20 to 30 seconds to loosen it.
Add the brown sugar, egg, baking soda, and salt, mixing to combine after each addition.
Add the cocoa powder, mix to combine and, with clean hands, knead in the cocoa powder until the cookie dough is a uniform, brown color with no streaks of peanut butter remaining.
Divide the dough into 12 equal portions of 1 1/4 tablespoons each (a #50 cookie scoop is ideal for this purpose), and place about 1 1/2-inches apart from one another on the prepared baking sheet.
Roll each piece of dough tightly into a ball between your palms, and press into a disk about 1/4-inch thick.
Place 2 to 3 chocolate chips on top of each disk, and press gently to help the chips adhere.
Place the baking sheet in the center of the preheated oven and bake for 12 minutes, or until the cookies are puffed and set toward the center.
The cookies will become more pale in color, and are set when the dough no longer glistens.
Remove from the oven and allow to cool for 10 minutes on the baking sheet or until firm.
Serve immediately or wrap tightly and store in the freezer.