- Heat oven to 350°.
- In large mixer bowl; cream butter and sugar until light and fluffy.
- Add eggs and vanilla; beat well.
- Combine flour, cocoa, baking soda and salt; gradually blend into creamed mixture. Stir in peanut butter or chocolate chips.
- Drop by teaspoonfuls onto ungreased cookie sheet. Bake 8-9 minutes. (Do not overbake; cookies will be soft. They will puff while baking and flatten while cooling.).
- Cool slightly; remove from cookie sheet onto wire rack. Cool completely.