I made this cake based on one I'd seen that won gold in the Cake Show 2009.
My version is a lot simpler...
I made a vanilla sponge using a recipe from the bbc good food website. I baked the sponge in a rectangular tin and once cooled I cut out the turtle shape, filled with jam and covered it completely in buttercream. To make the shell and scales I melted a bar of good quality dark chocolate and with a knife thinly spread it over greaseproof paper. Once set I then cut out the plates and stuck on to the buttercream.
For added effect I used brown sugar as sand around the base of the cake. (Crushed biscuit or golden caster sugar would give the same effect).