1 yellow cake mix
1 (11 oz. can) Mandarin oranges (drain and reserve juice)
3 eggs
1/3 c. vegetable oil
1 (20 oz. can) crushed pineapple (drain and reserve juice)
1 (12 oz. tub) Cool Whip
1 (3 oz. pkg.) vanilla instant pudding

Combine reserved juice with water to equal 1 1/3 cups. Blend cake mix with juice mixture, then add eggs and oil. Blend until moist then add oranges and beat for 2 min. Pour into two 8 or 9 inch round pans and bake at 350 for 35-35 minutes and cool completely.
Frosting:
Mix Cool Whip with crushed pineapple and slowly add vanilla pudding. Frost cakes and chill for several hours or overnight.