This under the sea cake is a plain chocolate cake that I made for a 3 year old (also made a tool cake for his twin brother). The icing is buttercream with fondant sea creatures.
To achieve the two-toned effect with the icing, I first used blue icing around the side then used teal around the top of the sides. I then blended them together with a spatula. I mixed the two colours together for the top of the cake then used white food colouring to create the top of the waves.
All the fish and seaweed are made from fondant and the sand is brown sugar. To make the island I used more cake and molded it then covered it with brown fondant. The writing is done in royal icing tinted moss green.