Mix flour, cocoa powder, baking soda and salt in a medium bowl and set aside.

Mix butter with sugar in a different bowl. Add vanilla and eggs and mix until smooth and fluffy.

Add flour mixture to wet ingredients and mix to combine. Then add peanut butter chips and stir until combined.

Drop onto greased cookie sheets and bake for 10-12 minutes or until bottoms are golden brown. The tops might still look doughy but they will cook as they sit on the cookie sheet. Let sit on cookie sheets for 5 minutes then remove to a wire rack and let cool.