Start by draining the mandarin oranges thoroughly, but keep the crushed pineapple with its juice — this adds extra flavor and moisture to the salad.
In your large mixing bowl, stir together the mandarin oranges, crushed pineapple (with juice), vanilla pudding mix, mini marshmallows, and chopped pecans (if you’re using them). Mix until everything is well combined.
Gently fold in the thawed whipped topping, being careful not to deflate it — this keeps the salad light and fluffy.
Cover the bowl and refrigerate the salad for at least 1 hour to allow the pudding to set and the flavors to meld beautifully.
Using the crushed pineapple with its juice keeps the salad moist and flavorful. Draining the pineapple will make the salad dry and less vibrant.
When adding the whipped topping, gently fold it into the mixture. This preserves the fluffy texture, making the salad airy rather than dense.
Refrigerating the salad for at least an hour lets the pudding set and flavors meld, giving you that perfect creamy consistency. If you have more time, chilling it longer intensifies the flavor even more.
The pecans add a delightful crunch, but if you prefer a nut-free version, feel free to leave them out or substitute with toasted coconut flakes or sunflower seeds for variety.