Hi, Jennifer, thank you I'm so glad you enjoyed it!
As soon as I saw your note, I tried the recipe with the only change being sugar-free Jello, but the texture wasn’t as creamy. I tried many iterations and this is what worked the best — with either sugar-free instant pudding or regular instant pudding. It's still not exactly the same, but close.
•Bring 1 cup of water and Jello to a boil. Remove from heat and stir 2 minutes.
•Add the dry pudding mix and stir for 2 minutes.
•Add 1 ¼ cup ice water and stir until it melts.
•Pour the mixture into a bowl. Fold in the Cool Whip.
•Chill 30 minutes or until firm enough to mound. Spoon into pie shell and chill 4+ hrs.

Thanks for the great question! Let me know if you try it and how it works for you.
Thanks, Cara

Well, darnit, I'm so sorry you ran into trouble! And I really can't say where you veered off course because I haven't run into that before. The two boxes of Jello mix and one box of pudding mix are the 4-serving size boxes, if that helps. As long as the mixture thickens up, you should be just fine. I'll be putting a video up of exactly how I made this pie in the next day or so, so maybe that will shed some light on something helpful if you should choose to take another swing at this recipe.

Hi Hope, Do you mean without any type of whipped cream or whipped topping at all? I would think so, though I haven't tried it. You might want to add a little more water, as the lemon flavor might be pretty intense without the Cool Whip. If you're looking for a substitute for Cool Whip, whipped cream should work just fine, it just might not stay firm for quite as long. I also like Truwhip, which is a "healthier" alternative to Cool Whip. I hope that helps!