Set aside some of the mandarin oranges, marshmallows, and coconut flakes to top the dessert at the end.
Boil 1 cup of water.
Add orange jello powder to a large mixing bowl, then slowly pour in the boiling water and whisk for 1 minute or until gelatin is dissolved. Whisk in 1/2 cup cold water to cool it down a bit, and then place the bowl in the fridge for 15 minutes.
Remove the bowl from the refrigerator, whisk in the vanilla pudding powder, and return it to the fridge for 15 minutes to let it set slightly.
Remove the bowl from the fridge and fold in the whipped topping.
Add the mandarin oranges, mini marshmallows, and coconut. Stir until combined, but do not over-stir.
Transfer to a pretty dish or bowl for serving, and top with the mandarins, marshmallows, and coconut flakes that you set aside earlier.
Cover the dish with a lid or plastic wrap and refrigerate for at least 2 hours to completely set before serving.
Notes
Best when chilled for several hours or overnight. This gives the flavors time to blend and the texture to firm up.
Can be made 1 day in advance, just give it a gentle stir before serving.