Preheat oven to 350 degrees and line a baking sheet with parchment paper.
In a small bowl, mix flour, cocoa, soda and salt using a wire whisk and set aside.
In another bowl, cream butter, sugar and peanut butter until light and fluffy. Add eggs and vanilla and mix until combined.
Add flour mixture to creamed mixture and mix until combined. Stir in chocolate chips.
Roll cookie dough into 1-1/2 inch balls and place on baking sheet.
Bake for 8-10 minutes. Cookies will still be soft but will set up after cooling. Place cookies on cookie rack to cool. Makes about 3 dozen cookies.
Notes
PRO TIP:
To make the cookies look like bakery style cookies I always save a few chocolate chips for the top after baking. Right after the cookies come out of the oven press in a few chocolate chips on top of the cookies.