1 box yellow cake mix
1/2 cup vegetable oil
1/2 cup chopped walnuts, if desired
1 can (11 ounce) mandarin orange segments, drained (reserve 1/3 cup liquid)
4 eggs
1 can (20 oz) crushed pineapple, undrained
1 box (4-serving size) vanilla instant pudding and pie filling mix
1/2 to 1 teaspoon grated orange peel, if desired
1 small container (8 ounces) Cool Whip frozen whipped topping, thawed
Heat oven to 350°F (325°F for dark or nonstick pan).
Grease or lightly spray bottom only of 13x9-inch pan.
In large bowl, beat cake mix, oil, walnuts, orange segments, reserved 1/3 cup orange liquid, and eggs with electric mixer on low speed 30 seconds, then on medium speed 2 minutes.
Pour into pan.
Bake 35 to 40 minutes or until toothpick inserted in center comes out clean.
Cool completely, about 1 hour.
Frosting:
stir together pineapple, dry pudding mix and orange peel.
Gently stir in whipped topping.
Spread on cake.