Preheat oven to 350 degrees F or preheat toaster oven to 400 degrees F. Sift flour, cocoa powder, baking soda and salt (optional) into a medium bowl. Set aside. In large bowl mix until creamy, butter, sugar, vanilla, eggs and peanut butter. Gradually add dry ingredients to creamy ingredients, mixing well after each addition. Then add chocolate chips (optional).
Drop by teaspoons onto ungreased cookie sheet.
Bake 8 - 10 minutes until centers are no longer wet looking and edges are set. Remove from oven and let cool. Enjoy!