Make the sponge cake. Beat the eggs (at room temperature) with the sugar, hot water, and a pinch of salt using an electric mixer or stand mixer. Beat until the mixture is light, fluffy, and very thick—this will take 10 to 15 minutes. At the end, add a little grated lemon zest.

Sift the flour and cornstarch together a couple of times, then gently fold them into the egg mixture a little at a time, using a spatula and mixing from the bottom up to keep the batter airy.

• Pour the batter into a greased and floured 7-inch (18 cm) cake pan, gently shaking to level the surface.

Bake the sponge cake right away in a preheated oven at 350°F (180°C), conventional setting, for about 20 minutes. Then lower the temperature to 340°F (170°C) and bake for another 15 minutes, making sure it doesn't get too dark. Check doneness by inserting a toothpick in the center—if it comes out wet, bake for 5 more minutes.

• Remove the cake from the oven and let it cool slightly, then take it out of the pan and turn it upside down onto a wire rack. Once cooled, wrap it in a clean towel and set aside.

Prepare the shortcrust pastry. Sift the flour onto your work surface and make a well in the center. Add the sugar, a pinch of salt, and the cold butter cut into pieces. Using your fingertips, mix the sugar and butter together, then add the lightly beaten egg and yolk, plus grated lemon zest.

Continue mixing, gradually incorporating the flour, until you get large, moist crumbs. Gently press the dough together to form a ball, flatten it, wrap in plastic wrap, and refrigerate for at least 1 hour.

Prepare the filling. Sift the ricotta into a bowl, add the sugar and a pinch of salt, and mix with a spoon. Add the liqueur, chocolate chips, and candied fruit, and mix again. Cover with plastic wrap and refrigerate.

• Now assemble the cassata. Grease a 8-inch (20 cm) cake pan, line the bottom with a circle of parchment paper, and flour the sides.