Preheat the oven to 350 F and line two baking sheets with parchment paper.
Using a hand-held or stand mixer, cream together the butter and sugar until fluffy and smooth.
Add the eggs, one at a time, mixing after each addition, and the vanilla extract.
In a separate bowl, whisk together the dry ingredients- flour, cocoa powder, baking powder, and salt.
Slowly beat the flour mixture into the creamed mixture until just combined and no streaks of white flour are left.
Using a rubber spatula, fold in the peanut butter chips until well combined.
Drop teaspoonfuls of batter onto the cookie sheets and bake for 8-10 minutes. Cool for 5 minutes on the baking sheet, then transfer to a cooling rack to cool completely. For an extra peanut butter touch, press extra chips into the cookies before they cool down completely.