Grease and flour a 9-inch springform cake pan and set it aside.
Combine in a medium size bowl the ricotta cheese, sugar, cinnamon, and orange zest and mix together with a spatula until the mixture is smooth. Place into the refrigerator.
Prepare the shortcrust: Add the butter, sugar, and lemon zest into a bowl and mix together with a whisk. In a separate bowl combine the flour and baking powder and mix to combine.
Gradually add the flour mixture to the egg mixture and using a spatula or fork mix both ingredients together until a dough is formed and developed.
On a floured working surface, divide two-thirds of the dough and shape round. Using a rolling pin, roll out the dough to about 2 inches in thickness.
Carefully transfer the sheeted dough into the cake pan and line the bottom and sides.
Spread half of the biscuit crumbs onto the top of the shortcrust dough.
Remove the ricotta filling from the refrigerator and beat with a hand mixer for a few 60 seconds. Add the chocolate chips, or the candied fruit and fold them into the mixture.
Fill the cake pan with the ricotta filling and level the top with an offset spatula or the back of a spoon, then sprinkle the remaining biscuit crumbs onto the top.
Round the 1/3 piece of dough and roll it out to 2 inches. Place it over the filling and cut off the excess dough. Using a knife or a fork poke the top of the shortcrust to allow steam to escape during the baking.
Place the cake pan into the refrigerator for 30 minutes.
In the meantime preheat the oven to175°C (350°F).
Bake the cassata cake for 60-70 minutes, the center of the cake will be firm.
Remove from the oven and allow to completely cool in the baking pan.
Once cooled turn the cake over onto a serving plate.
Sprinkle with some icing sugar and serve.
Enjoy!