Follow the instructions on the cake mix EXCEPT for the water.
Pour juice from the mandarin oranges into a measuring cup.
Add enough water to the mandarin orange juice to meet the required "water" measurement on the cake mix package.
Add to cake mix.
Once cake batter is mixed fold in the drained can of mandarin oranges and mix to break up orange bits.
Bake according to package directions.
Whipped Frosting
Whisk crushed pineapple (and juice) with packet of instant vanilla pudding.
Fold in half of the whipped topping until incorporated; Once combined, add the remaining half and fold until combined.
Once all the cool whip is folded in, refrigerate until cakes are cooled and ready for frosting.
After your cake is cooled, frost the top of the first layer and the second cake and frost the remaining cake heavily.
You can leave it just like that or you can top it with strawberries, pineapple, mandarin oranges and so on.
Notes
Go a little nuts: Try adding some crushed nuts to the frosting to up your flavor profile
Decorate with different fruits: Use your imagination and try using blueberries, strawberries or whatever your family likes to decorate your Pig Pickin Cake.
Less liquid helps: When making the icing, make sure the pineapple is well drained and fairly dry to keep it firm.