In a mixing bowl, blend the sheep's milk ricotta with 1 1/2 cups of sugar, the seeds from half a vanilla bean pod, and a few drops of orange blossom water until creamy.

Incorporate the chopped dark chocolate, 1/3 cup of coarsely chopped pistachios, and the assorted candied fruit cubes into the ricotta mixture.

Line a 9-inch cake pan with plastic wrap for easy removal later.

Roll out the pistachio marzipan on a surface dusted with powdered sugar until about 1/8 inch thick. Cut strips to line the inside of the cake pan.

Slice the sponge cake into 1/2 inch thick pieces and arrange them at the bottom of the prepared cake pan.

In a small saucepan, boil 1/3 cup of water with 1/4 cup of sugar. Add a strip of lemon peel or a piece of vanilla bean pod for flavor, then add 2 tablespoons of lemon liqueur. Allow to cool.

Lightly brush the sponge cake with the soaking liquid.

Pour the ricotta filling into the cake pan over the sponge cake. Add more layers of sponge cake on top, pressing down gently and brushing with the soaking liquid again.

Fold the plastic wrap over the top and refrigerate for at least 4-8 hours to set.

Melt the fondant cake icing over low heat until fluid. Carefully turn the cassata out onto a serving dish and pour the melted fondant over the top.

Spread the fondant evenly with a spatula and refrigerate for another hour to set.

Once set, decorate the top with candied cherries, orange slices, and citron.