Place sugar, flour and salt into saucepan. Set on low heat. Slowly stir in the cream. Keep whisking, bring to a boil.
Take off heat. Temper your eggs by very slowly pouring in about a cup of the hot mixture into your yolks, whisking the whole time. Put saucepan back on heat and slowly pour egg mixture back in while whisking, whisking, whisking.
Bring to boil then immediately remove from heat. Whisk in your vanilla and cool whip. Now, finally, you can stop whisking.
Set aside. Now work on your pudding, making it according to the directions on the package. I like the instant pudding where all you do is whisk in 2 cups of milk and you are done.
Slice banana into thin disks. Stir half of the disks into the custard, slightly mashing them a bit. Slice the other half of the banana into the pudding.
Put both containers into fridge, covered, to chill for 3 hours.
When ready to make your pie, layer custard down first (as it is heavier than the pudding), then the pudding. Chill in freezer for about two hours, to let it all set. Garnish the top with dollop of cool whip, then lemon n lime zest, more banana slices, strawberry slices, toasted coconut, or, as I have in my pic, with shaved chocolate!