Drain the pineapple but save the juice.
Mix pineapple juice and vanilla pudding together in a medium saucepan.
Cook over medium heat until thick. Mixture will get clearer.
Let cool for a few minutes, then with a sheet saran wrap, place over the pudding mixture, pressing it into the mixture all across the top of your sauce pan. Put in refrigerator to chill. The saran wrap should prevent your pudding from getting a "skin".
When the pudding mixture is chilled, add the drained pineapple, drained mandarin oranges and maraschino cherries.
Cut your bananas and add to the fruit salad right before serving to avoid the bananas browning.