In mixing bolw, cream butter and sugar. Add egg whites, beat well. Blend in peanut butter and vanilla. Combine flour, baking soda and salt. add to creamed mixture and mix well. Stir in chopped candy bars. Shaped in 1 1/2 inch balls and place on greased baking sheets. Bake at 350 for 10-12 minutes or til golden brown. Cool on rack. Posted to Fabfood 9/98 Contributor: Taste of Home, June/July '98