Preheat the oven to 375°F. Line a couple sheet pans with parchment paper.
In a bowl, whisk or sift together the flour, cocoa powder, baking soda, and salt. Set aside.
In a mixer, beat together the butter, brown sugar, and sugar until well combined, about 1 minute. Beat in the eggs and vanilla.Stir in the flour mixture until just combined. Stir in the peanut butter chips.
Scoop 1 1/2-inch sized balls of dough onto the lined sheet pans, spacing them about 1 1/2-inches apart. Bake for about 10 minutes or until the cookies are just set and lightly browned. Let them cool for a few minutes and then transfer to a wire rack to finish cooling.