Preheat oven to 350-degrees F.
Combine the softened butter or margarine and the peanut butter in a large bowl. Beat with an electric mixer on medium speed until the mixture is light and fluffy. Gradually add the granulated sugar and brown sugar. Beat in the eggs and vanilla until well combined; set aside.
In a medium bowl, stir together the flour, baking soda and salt. Add the flour mixture and chocolate pieces to the dough. Stir until the dough is well blended.
Drop the batter by tablespoonfuls onto lightly greased cookie sheets.
Bake for 9 to dozen minutes or until the edges of the cookies are lightly browned or a slight impression remains when the cookies are lightly touched with a fingertip.
Transfer the cookies to a wire rack to cool completely.
This recipe is from "America's Best-Loved Community Recipes" published by Better Homes and Gardens, 1994. It was originally published in "Home Cookin' Mount Zion Heritage Cookbook" published by the Mount Zion Cemetery Association, Apple Springs, Texas.