In a large bowl, cream the shortening, peanut butter and sugars until light and fluffy. Beat in eggs one at a time; beating well after each addition. Beat in vanilla. Combine the flour, baking soda and salt; add to creamed mixture and mix well. Stir in peanuts if desired.
Drop by rounded teaspoonfuls 2 in. apart onto ungreased baking sheets. Flatten with a fork if desired. Bake at 350° for 10-12 minutes or until set.