I bought a pineapple flavored cake for this Luau Cake. I baked two round cakes and layered it with frosting I added coconut extract to. I then cut a small "pond" in the top layer of the cake.
I added blue food color to the remaining frosting (2 cans of vanilla worked perfect). Before frosting the cake, I took blue jello and made it less water than the package call for and set it aside(maybe even in the fridge for a brief few minutes, you don't want it to fully set right away.)
I frosted the entire cake with blue icing, paying extra attention to the pond. I then filled the pond with the blue jello. I put the Luau cakein the fridge to let the jello set completely.
Being that it wasn't with the full amount of water, it does not take long. While this process is taking place, grind or mash very finely some Nilla wafers for your sand. Sprinkle sand on your island. I topped the top with a plastic palm tree and some hula dancers and the under water scene is rainbow goldfish crackers and gummy fish.
I got the idea from a magazine, but put my own twists to it.
The bottom layer of this Hawaiian Luau Birthday Cake is a 2 layer 10 inch round cake covered in cream cheese frosting. The decoration of this layer was the easiest as I just took 2 leis and placed them around the cake.
The middle of the cake is 2 beta fish tanks complete with 2 live beta fish. I supported the tanks on the bottom layers with 4 support pillars in the bottom layer and a cake board on top of them. I stretched out another lei and placed it between the cakes for the flowers on each side.
The top layer of cake is another 2 layer 10 inch round cake frosted with cream cheese frosting. The edge of the cake is surrounded by Pirouette cookies to make the 'fence' look. The sand is crushed up graham crackers. I used scrapbook stickers as the decorations for the boats and seashells. The tiki hut is 2 small cardboard boxes surrounded by Popsicle sticks. I found the thatch top on a hamster house so cut it off and used it.
I made this Luau cake for my daughter's second birthday - a Luau Party. A large rectangular cake ( I used Funfetti) and large cupcake, top cut off to make island, were first very lightly iced with cream cheese frosting.
I then used blue food coloring to tint the icing to make water, it looks the best when you don't completely mix it in so you have a little white as well as lighter and darker blue. The sand was made from crushed Nilla wafers and used a strainer to sprinkle heavily on the cake. If you try to sprinkle it with your fingers it will clump up.
I added gummy clown fish and a couple of gummy sharks circling the island. Try to have a least as many fish as you have kids at your party because they'll all want one! The tiki hut and palm trees are from a Pirate play set that I purchased from the dollar store. Everyone loved it and I was proud of myself for making it instead of purchasing it!