In a smaller bowl, combine dry ingredients (flour, baking soda, salt, and cocoa)
In a large bowl, cream together butter and sugar. Add eggs and vanilla. Mix well.
Add the dry ingredients to the wet ingredients. Mix until completely combined. Make sure it's the correct consistency. Add a little more flour if the batter is sticky.
Add the peanut butter chips and mix well.
Use a cookie scoop (small cookies) or ice cream scoop (large cookies) on a cookie sheet about 2 inches apart.
Place in a preheated oven for 8-10 minutes (small cookies) or 12-14 minutes (large cookies) at 350°.
Cool for 2 minutes, then remove from cookie sheet to wire rack.