In a bowl, dissolve the orange Jell-O in 1 cup boiling water. Stir in 1 cup cold water. Refrigerate until slightly thickened but not fully set (about 1 hour).
In another bowl, whisk together the vanilla pudding mix and milk until smooth. Let it thicken for 5 minutes.
Fold the pudding mixture into the prepared Jell-O.
Gently fold in the whipped topping until light and creamy.
Stir in the mandarin oranges.
Cover and refrigerate for at least 2 hours before serving to let the flavors meld.
Serving and Storage Tips
