In a medium bowl, use a potato masher to break up apples in the filling; set aside. In a large mixing bowl, cream together butter, white sugar, and brown sugar. Stir in eggs, apples, and vanilla extract until well blended. Sift together flour, baking soda, cinnamon, and salt. Stir into apple mixture, then stir in raisins and walnuts. Pour batter into prepared pan.