Make the chocolate sponge cake. Grease the hemispherical cake tin well and dust with some flour. In a mixing bowl, cream the butter and sugar until pale and fluffy. Add the eggs one at a time and mix well until the mixture looks smooth. Mix in the vanilla essence. Sift in the flour and mix (but try not to over mix). Pour the mixture into the cake tin and bake in the oven preheated at 160°C for about 1 hour or until the testing skewer comes out clean. Cover the cake with foil towards the end of baking time to prevent burning. When baked, leave the cake in the tin to cool down, then take out of the tin and wrap it up in cling film.

Beat the butter with the icing sugar until fluffy and add the orange essence and the syrup to make orange butter cream icing. Slice the cake horizontally into half, sandwich some icing and thinly cover the cake with the remaining icing. Set it aside/put it in a fridge.

Make the glaçage. Soak the gelatin leaf in water (not included in the ingredients list). Put the cocoa powder in a saucepan and add the water to make a smooth paste. Add the cream and sugar to the pan, mix, and put the pan on low to medium heat until it just starts bubbling on the edge. Stir the mixture until it looks glossy. Remove the pan from the heat and let it cool until you can just keep touching the pan (usually 7 - 8 mins but it takes longer on warm days). Squeeze out water from the leaf gelatin, add it to the glaçage mixture and mix well. When the gelatin is disolved sieve the glaçage mixture and let it cool to about 30°C.

When the glaçage is set, carefully lift it up and place it on a plate/cake stand round side down. Gently pour the remaining glaçage on the top/flat side. Wrap some Ferrero Rocher with gold leaf and pile them up. Carefully place the chocolate cage over the cake and it's done.