prepare yellow cake mix as directed on box except add enough water to mandarin orange juice to make desired amount for cake preparation. Add mandarin oranges and mix. Pour into prepared 9x13 pan and bake.
in separate bowl, combine pudding mix, pineapple, and cool whip. Refrigerate until ready to top cake.
cool cake until completely cooled then top with cool whip topping. Enjoy and refrigerate uneaten cake to keep topping from going sour.