Start this recipe with the ricotta filling. Place the ricotta in the bowl of an electric mixer and beat lightly for 1 minute. Add in the orange zest, vanilla, icing sugar and chocolate chips and mix till smooth. Add in the double cream and mix to incorporate. Next, cut the sponge round in half. Place 1 piece onto a board, fill with half of the ricotta filling. Place on the remaining sponge and cover with the remaining ricotta. Smooth out and place into the fridge to set for 1 hour. When ready, cover the sides with the green marzipan. To decorate the top, mix the icing sugar with a little water to make a soft glaze icing. Pour over the ricotta on top, smooth out and decorate the top with candied peel, red cherries and glace fruit.