From can of oranges reserve liquid and 8-10 slices for garnish.
Mix remaining oranges, cake mix, eggs, oil, and vanilla with electric mixer until smooth.
Pour the mix equally into the two pans and bake for 25-30 minutes or until toothpick inserted in center comes out clean.
While the cakes are baking, whip together both containers of whipped topping, the pinnapple with juice, and both boxes of pudding with a wooden spoon or similar. Set aside.
When cakes are finished baking and cool enough to handle, turn them out onto separate plates, poke a few holes in both layers with a knife, then pour the juice from the mandarin oranges over top of the cakes. (It makes it them more moist.)
When cakes are fully cooled spread frosting on the first layer, top with the second cake layer, and cover with more frosting on the top and sides. Add remaining oranges on top for decoration.
This recipe makes a lot of frosting because I hate running out of frosting when icing a layer cake! Don't be afraid to lick the spoon...a lot. Enjoy!