Punch Bowl Cake

1 (18.25 ounce) box cake mix
2 small boxes vanilla pudding
2 quarts fresh strawberries or 2 cans cherry pie filling
    (reserve some for top)
6 to 8 bananas, sliced
1 large can crushed pineapple, drained
1 1/2 cups coconut
1/2 cup chopped nuts
1 (12 ounce) container Cool Whip