Step 4: Prepare the Frosting
In a large bowl, mix the instant vanilla pudding with the full 20 oz can of crushed pineapple (including the juice) until combined. Fold in the thawed whipped topping until the frosting is light and fluffy.
Step 5: Frost the Cake
Spread the pineapple-whipped topping evenly over the cooled cake. Decorate with the remaining can of drained mandarin oranges.
Step 6: Chill and Serve
Refrigerate the cake for at least 30 minutes before slicing. This helps the pudding set and allows the flavors to meld beautifully.
