Preheat the oven to 180°C.
Beat egg yolks with icing sugar until creamy.
Whisk egg whites in a separate bowl until stiff.
Fold whites, flours, and vanilla into the yolk mixture.
Butter a tray, line with paper, and pour in the mixture.
Bake for 30 minutes until golden and springy.
Cool the sponge and slice horizontally into 3mm layers.
Process ricotta and caster sugar until creamy.
Stir in the candied fruit and chocolate chips.
Line a basin with cling film and a layer of sponge.
Brush the sponge with limoncello.
Pack the ricotta filling into the lined basin.
Cover the top with a sponge disc and wrap with film.
Weight with a plate and freeze overnight.
Invert onto a plate, remove film, and dust with cocoa.