To make the pastry

Place the flour in a large bowl and add the diced butter. Pinch the pieces of butter with the tips of your fingers to break them into very small lumps and keep working the mixture until it resembles fine, loose breadcrumbs.

Make a well in the sandy mixture and add the sugar, egg, lemon zest, vanilla and salt. Mix in the egg and sugar with your hands first, then gradually incorporate the flour mixture. Once the eggs are incorporated, turn the mixture on to the worktop, flatten it with the palms of your hands, lift one side with a scraper and fold it in half. Repeat the flattening and folding until homogeneous. Wrap in clingfilm and chill it in the fridge for at least 30 minutes.

To make the filling

Soak the sultanas in a small bowl with the vin santo. Place the milk in a medium pan and add vanilla, nutmeg, cinnamon and salt, then bring it to a simmer over a low-medium heat. Stir the milk often to avoid it sticking to the bottom of the pan and keep a close eye on it when it starts simmering as it may start boiling and overspill. When the milk just starts to simmer, reduce the heat and add the rice. Let it simmer until the milk has been fully absorbed; it will take 25–30 minutes. The resulting mixture will look thick and creamy. Stir the rice often while it cooks, and continuously when the mixture starts thickening up as it might stick to the pan and burn easily otherwise.

Remove the mixture from the heat and sift in the cocoa powder, then add sugar, pine nut kernels, sultanas and the vin santo, candied peels and chocolate chips. Mix while the mixture is still hot to melt the chocolate. Once all ingredients have been fully combined, add the eggs and mix until fully incorporated. Line the surface with clingfilm and set aside to cool to room temperature, then chill in the fridge for at least 1 hour.

To Assemble

Grease a 27cm (10¾in) springform tin well, including the sides, and line the bottom with a disc of baking paper. Place the shelf in the lowest position in the oven and preheat it to 180°C (350°F/Gas mark 4).

Take the pastry out of the fridge, unwrap it and roll it to a thickness of 5mm (¼in) on a well-floured worktop, shaping it into a disc. Wrap the pastry around the rolling pin and unroll it over the prepared tin. Gently fit the pastry into the tin so that it fits snugly. Let the excess pastry hang out of the tin sides without trimming it for the moment: this helps holding the sides of the pastry casing up while you fill it and shape it. Prick the bottom of the pastry casing in several places with the prongs of a fork.

Spoon the filling into the pastry casing and level it off with the back of a spoon or, better, with a small offset spatula. Trim off the excess pastry by running a blunt knife along the rim of the tin.

Now shape the ring of pastry above the filling to form bischeri around the pie. Starting from the side of the pie closest to you, use a sharp knife to cut a slit in the pastry ring: cut from the bottom of the pastry (i.e. level with the top of the filling) upwards, at a 45° angle. Fold the small flap of pastry generated by the cut on itself, so that the cut edge now lays flush with the filling top. This will have formed a pointed shape of pastry, twice the thickness of the rest of the pastry: your first bischero. Progress by cutting and folding the pastry all around the pie to shape the full ring of bischeri.

Now prepare the decorative strips for the top: briefly knead the pastry offcuts into a thick sausage and roll it to a thickness of 5mm (¼in), shaping it as a narrow sheet, 30cm (12in) long. Using a crimped pastry wheel, cut 2cm (¾in) wide strips off the pastry sheet and arrange them over the top of the pie in a geometric diamond pattern.

Bake for about 53–55 minutes, or until the bischeri start to brown. While baking, the filling will swell as some of the moisture turns into steam: this is to be expected and the pie will settle back almost to its original height upon cooling. Let the pie cool completely before taking it out of the tin.