Dissolve the Gelatin: In a large mixing bowl, add the boiling water and the orange-flavored Jell-O. Whisk vigorously until the gelatin powder is completely dissolved.

First Chill: Pour the cold water into the bowl and stir. Place the bowl in the refrigerator and chill for 20 minutes, or until the mixture has visibly thickened.

Incorporate the Pudding: Remove the bowl from the fridge. Add the dry instant vanilla cheesecake pudding mix and whisk until smooth and combined. Return the bowl to the refrigerator and chill for another 20 minutes until it thickens further.

Fold in the Goodies: To the thickened mixture, add the Cool Whip, drained mandarin oranges, and miniature marshmallows. Using a rubber spatula, gently fold everything together until well mixed. (Do not stir vigorously, or the fluff will deflate!)

Final Chill: Cover the bowl and chill in the refrigerator for 1 to 2 hours to let the flavors meld and the marshmallows soften.

Serve: When ready to serve, scoop into individual bowls and garnish with extra oranges, marshmallows, and mint leaves if desired. Enjoy!