Well, I finally broke down and made the rainbow cake. I love it and how it turned out - only next time I might need to buy some more cake pans so I can do more than 2 layers at the time - and maybe make the layers a bit smaller. The Mother's Restaurant recipe for whipped cream icing (usual topping for coconut cream pies) worked like a charm. And go Moist Deluxe cake mix - worked like a charm with the WIlton icing color set. Next up - the big reveal photo!