To speed up making the shortcrust pastry, use a food processor with blades.
Add the flour and cold butter cut into small pieces.
Pulse until the mixture looks sandy, then add the sugar, eggs, and lemon zest.
Mix until the dough comes together and forms a ball.
Remove the dough from the mixer and knead it lightly by hand to form a disk.
Refrigerate for at least one hour.

Prepare the filling.
Start cooking the rice with the water and a pinch of salt.
Once it starts to boil, add the milk, 1/4 cup sugar (50 grams), butter, and the zest of half a lemon and half an orange.
Cook over low heat until all the liquid is absorbed, about 20–30 minutes.
Remove the citrus peels, transfer the mixture to a bowl, and let it cool.

Sift the ricotta through a fine mesh strainer, add the remaining sugar, eggs, and mix with a whisk.
Grate the remaining citrus zest and add it to the mixture along with the cinnamon and orange blossom extract.
Once the rice mixture has cooled, add it to the ricotta mixture one spoonful at a time, mixing well to create a creamy filling.

Bake at 350°F (180°C): 10 minutes on the lowest oven rack, then about 1 hour on the center rack.
Check the top and inside of the tart, and if needed, bake for another 5–10 minutes until golden on top and set inside.
Once baked, turn off the oven, open the door, and let the tart cool completely.