Combine cake mix, oil, eggs, and undrained oranges; mix well.  Place in greased and floured 9 x 13 pan.  Bake at 350 for 35 min.  Let cool in pan completely.  combine undrained pineapple, and pudding mix; fold in topping.  Spread on cake; refrigerate.

Delicious, and not too sweet.  This needs to stay in the fridge once you top the cake, but you can mix up the topping and keep it separate, then add a spoonful or so over a square of the cake at serving time.