Preheat oven to 350 degrees F. Line a baking sheet with parchment paper or silicone baking mat; set aside.
In a medium bowl, whisk together the flour, baking powder and salt; set aside.
Using an electric mixer, beat together the butter and sugar on medium-high speed until light and fluffy, about 2 to 3 minutes. Scrape the sides of the bowl, then add the eggs one at a time, scraping the sides of the bowl as needed. Add the cocoa powder and vanilla extract, then beat on medium speed until fully incorporated, about 1 minute, stopping to scrape the sides of the bowl once. Reduce the mixer speed to low and add the flour mixture, beating only until incorporated. Fold in the peanut butter chips with a rubber spatula and give the dough a final mix with the spatula to ensure all of the ingredients are wholly incorporated.
Divide the dough into 9 (giant) or 12 (very large) equal portions. Roll each into a ball and place on the prepared baking sheet. Pat the tops of the cookies ever so slightly (don't press down too hard).
Bake for 16 to 20 minutes, or until the tops of the cookies feel set when touched lightly. Let cool for 5 minutes on the cookie sheet, then remove to a wire rack to finish cooling. Leftovers can be stored in an airtight container at room temperature for up to 4 days.