Prepare the Jello: In a large mixing bowl, dissolve the Orange jello in 1 cup of boiling water, stirring until completely dissolved. This should only take a couple of minutes.
Mix in Cold Water: After the jello has dissolved, add 1/2 cup of cold water and mix well. This will quickly cool down your jello mixture.
Chill Until Partially Set: Refrigerate the jello mixture for about 1 hour, or until it’s slightly thickened but not fully set.
Fold in Toppings: Once the mixture has thickened, fold in the whipped topping and chopped mandarin oranges gently until well combined.
Set It All Together: Pour the mixture into a serving dish or individual cups and refrigerate until fully set, which will take another 2 hours.
Serve and Enjoy: Once set, serve your Creamsicle Orange Fluff chilled. Enjoy the refreshing, creamy texture!