Preheat the oven to 180C/350F/Gas 4. To make the sponge, beat the egg yolks with the icing sugar until you obtain a creamy consistency.
In a separate bowl, whisk the egg whites until stiff. Gently fold the stiff egg whites into the creamy egg yolk mixture, followed by the flours and vanilla essence.
Butter a rectangular baking tray and line with greaseproof paper.
Pour in the mixture and bake in the preheated oven for 30 minutes or until lightly golden brown and springy to the touch.
Remove the sponge from the oven and allow to cool, then remove from baking tray and carefully cut in half lengthways to obtain a thickness of 3mm for each layer of sponge.
To make the filling, place the ricotta and sugar in a food processor and whiz until creamy.
Place in a bowl and stir in the candied fruit and chocolate chips.
Line a pudding basin with cling film, leaving excess hanging over the edges.
Then take one half of the sponge and line the pudding basin with it. With the help of a pastry brush, wet the sponge with limoncello.
Fill with the ricotta mixture and pack well in. Take the other half of the sponge, cut into a round disc and fit over the top.
Wrap the excess cling film over the top and place a heavy plate on top.
Put in the freezer overnight. When you are ready to serve the zucotto, remove the heavy plate and unfold the excess cling film. Place a serving plate over the top and gently tip it upside down.
Remove the cling film and dust with lots of sieved cocoa powder. Cut into slices and serve with a mixed berry coulis.