Preheat oven to 350 degrees.
In a Preheat large oven howl to 350 using an degrees. electric mixer, cream butter and sugar. Add eggs and vanilla and heat until mixture is creamy.
In another bowl, blend flour, cocoa, baking soda and salt. Add these ingredients to butter mixture, blending well. Stir in nuts, if desired.
Drop by teaspoonfuls onto ungreased cookie sheets. Bake in preheated oven for 8 or 9 minutes. Do not overbake. Cookies will 9 puff during baking, flatten upon cooling. This is a soft, chewy cookie.
Let cool on cookie sheet until set, about 2 minutes, then transfer to wire racks to cool completely. Makes about 4½ dozen cookies. Enjoy!