Cherry Supreme

1 (18.25 ounce) box cherry supreme cake mix
1 medium can crushed pineapple
1 small box cherry Jell-O
4 eggs
2/3 cup vegetable oil
1 can cherry pie filling
1 container Cool Whip, thawed

Drain juice from pineapple and save. Mix all other ingredients together. Bake at 350 degrees F for 40 to 45 minutes in a 9 x 13-inch cake pan. When cake is done and still hot, pour pineapple juice over top of cake. Cool cake. Top cake with Cool Whip. Add cherry pie filling on top. Refrigerate.