Mix flour, salt, and baking soda together. Set aside. Mix butter and peanut butter together. Add both sugars to butter mixture. Mix well. Add eggs to butter mixture and beat well. Stir flour mixture into peanut butter mixture. Drop dough from a teaspoon to an ungreased baking sheet. Flatten with a fork. Bake @ 375 degrees for 10 to 15 minutes or until lightly browned. Yields: 4 to 5 dozen.