Preheat the oven to 350, grease a 9x13 baking dish and set aside.
Combine the cake mix, eggs, oil and oranges and beat until well mixed and the oranges are incorporated. You will see small bits of oranges, but there shouldn't be any large chunks.
Pour the batter into the pan and bake on the center rack 20-25 minutes until a toothpick inserted in the center comes out clean; rotating them halfway through the cooking time. Start checking your cake at 20 minutes.
For the frosting
Combine the pineapple, filling mix, sugar and sour cream and beat well until all ingredients are combined and thickened. Fold in the whipped topping.
Frost the cooled cake and store in the refrigerator.
Notes
Note 1: Traditionally I make this cake with the cheesecake filling packet found in a Jell-O No Bake Cheesecake. You can use that or an 11 ounce box of instant cheesecake pudding. Note 2: Whipped topping can be substituted with stabilized homemade whipped cream. This cake tastes best if it can sit in the fridge for one to two days before eating.