Drain the ricotta in a colander for 1 to 2 hours. Stir in the superfine sugar, cover, and chill for 1 hour.

Heat the oven to 350°F and grease and flour your 10-inch cake tin.

Whisk the eggs, sugar, vanilla, and salt for 10 to 15 minutes until the mixture looks pale, thick, and ribbon-like.

Fold in the sifted flour in 2 or 3 additions gently.

Pour the batter into the prepared tin and bake for about 30 minutes until golden and springy.

Let the cake cool completely on a rack.

Press the chilled ricotta through a fine sieve for a silky texture.

Stir in the chopped dark chocolate and 1 tablespoon of liqueur, then set aside.

Boil the sugar and water for about 5 minutes, then cool slightly. Mix the ground almonds with the powdered sugar, add enough syrup to make a soft dough, and knead in a small drop of green coloring.

Line the sloped tin with plastic wrap, leaving extra hanging over the sides.

Roll the marzipan about 1/4 inch thick and cut it into strips as tall as the tin sides.

Slice the cooled sponge into 1/2-inch slices and cut pieces to fit.

Press sponge and marzipan pieces alternately around the sides of the tin, cover the base with sponge strips, and brush everything with liqueur.

Spoon in the ricotta cream and level the top, then cover with the remaining sponge, brush again with liqueur, fold over the plastic, and refrigerate for at least 6 hours or overnight.

Turn the cake out onto a plate and peel away the plastic.

Stir the powdered sugar with lemon juice and a little water until it is fluid but spreadable, then spread it over the top.

Let it set for a few minutes, and finish with chopped candied fruit.

Chill until ready to serve.