Heat your oven to 350 degrees. In a small bowl, sift the flour, cocoa powder, baking soda and salt. Set this aside for now.
In a stand mixer or with a hand mixer cream the softened butter and the sugar. Cream until the butter has lightened and the sugar is less gritty. Add the eggs in one at a time and mix fully after each addition. Scrape down the sides with a rubber spatula in between. Add in the vanilla and blend for another minute.
Using your rubber spatula, mix in the flour/cocoa mixture until almost everything is mixed together. Add in the peanut butter chips and continue to mix until everything is well combined and no more flour is showing. This is a thick batter, so make sure everything is well incorporated, but do not over mix.
Using a cookie scoop, scoop out cookies onto a non-stick baking pan. If not using a non-stick baking pan, grease the pan and/or uses parchment paper on the bottom of the pan. The scoop I used made 30 cookies. You will yield between 30-36 cookies from this batter depending on size.
Bake for 8-10 minutes or until the cookies are done on the top, but not over baked. Half way through, I recommend that you lightly press them down with the back of a measuring cup. This will help ensure even baking and even sizing in the finished product.
Remove from the oven and let cool on the pan for 1-2 minutes. Move them to a cooling rack and let them cool completely. Plate up and/or pack them to go and Enjoy!