Colorful Jell-O salad with fruit and whipped topping is a nostalgic, retro family potluck tradition. This fun, jiggly side dish-dessert hybrid brings back memories of family gatherings past.
In a large heatproof bowl, pour 2 cups boiling water over the Jell-O gelatin mix. Stir for at least 2 minutes until fully dissolved.
Add 1 cup cold water to the dissolved gelatin and stir to combine, ensuring the temperature drops slightly.
Gently stir in drained pineapple tidbits and mandarin orange segments. Add in mini marshmallows to the mixture, distributing evenly.
Transfer the mixture to a 9x13 inch dish and refrigerate for at least 2 hours until firmly set. Do not disturb during chilling to ensure a smooth surface.
Once fully set, evenly spread thawed whipped topping over the Jell-O layer. Chill for an additional 30 minutes before serving for best texture.