To prepare the sponge cake: Beat, using an electrical mixer, the eggs, sugar, lemon zest, vanilla for 8 to 10 minutes until foaming; add the flour gradually using a spoon and mix slowly.
Pour the mixture into a greased 30x25 cm baking tin and bake in a preheated oven at 180 °C for 25 to 30 minutes or until a skewer inserted in the middle comes out clean.
To prepare the chocolate mousse: Put the gelatin in cold water and keep aside for 5 minutes.
Melt the chocolate and warm up the NESTLÉ Sweetened Condensed Milk. Strain the gelatin and melt it in the microwave for 15 seconds or on direct fire, add it to the NESTLÉ Sweetened Condensed Milk and mix.
Add the melted chocolate to the mixture and mix well. Using a spoon, slowly pour the whipped cream and mix all together. Avoid over-mixing the cream which damages its texture.
To prepare the butter cream: Using an electrical mixer, beat the butter, NESTLÉ Sweetened Condensed Milk and vanilla for 6 minutes or until the color turns to white.
To prepare the sugar syrup: Bring the water and sugar to boil, and keep aside to cool down.
Add the vanilla essence just before use. Use cold.
Finally: Cut the sponge cake into 3 layers. Put one layer on a wooden or carton base; brush it with sugar syrup, and using a spatula spread evenly half the quantity of the chocolate mousse on the sponge. Put the second layer and repeat the same process. Put the last layer on top and keep the cake in the fridge for at least 1 hour.
Cover the whole surface of the cake using the cream (save some to make a river of cream). Using your hands, cover the sides of the cake with the coconut.
Wear gloves and mix the coconut with the green food coloring and cover the top of the cake.
Color the remaining butter cream with the blue food coloring to make a small river before sprinkling the green coconut. Add some plastic animal toys on the top.