How do I make household version of the roast pig cake by Kathy Scott?

It is very easy to prepare the Kathy Scott roast pig cake:

The ingredient are 1- 18 ounce of yellow cake mix, 11-ounce may mandarin oranges with juice, 4 eggs, 1/2 cup of vegetable oil, 9 ounce of carton frozen whipped topping which should be thawed.

The procedure is as follows. Preheat the oven to 350 degrees. Grease and flour four 9 inch cake pans. In a mixing small bowl, combine the cake mix, mandarin the oranges, mandarin the orange juice, eggs and the oil. Beat it for 2 minutes with electric mixer. Put in the pans and then bake for about 20 to 25 minutes or until the cake tester comes out clean. Cool it in pans for about 5 minutes, turn out of the pans and finish the cooling on wire racks. In a mixing bowl, combine some of the whipped topping, pineapple, juice from can and then to vanilla pudding mix. Frost between the layers and then on top of the cake. Now, you have your cake ready.