In a large mixing bowl, combine the sifted flour, granulated sugar, and salt. This ensures even distribution of the ingredients.

Add the cold, cubed butter to the flour mixture. Use a pastry cutter or your fingers to mix until the mixture resembles coarse crumbs. This helps create a flaky texture.

In a separate bowl, whisk together the egg and vanilla extract. Add this to the flour mixture and stir until the dough comes together. Avoid overmixing to keep the crust tender.

Form the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 30 minutes. Chilling the dough helps prevent shrinkage during baking.

In a large bowl, combine the ricotta cheese, sifted powdered sugar, and eggs. Whisk until smooth and creamy. This ensures a uniform filling without lumps.

Add the vanilla extract, lemon zest, orange zest, dark chocolate chips, and cinnamon. Stir until well combined. The zests add a fresh flavor that complements the richness of the ricotta.

Preheat your oven to 350°F (175°C).

On a lightly floured surface, roll out the chilled dough to fit your 9-inch pie pan. Transfer the dough to the pan and trim any excess. This forms the base for your pie.

Pour the ricotta filling into the prepared crust, spreading it evenly. This ensures every slice has a balanced filling.

Bake in the preheated oven for 50-60 minutes, or until the filling is set and the crust is golden brown. The baking time may vary, so check for doneness.

Once baked, remove the pie from the oven and let it cool completely before slicing. This helps the filling set further.

In a small bowl, whisk together the sifted powdered sugar, milk, and vanilla extract until smooth. Adjust the milk to reach your desired consistency.

Drizzle the glaze over the cooled pie before serving for an extra touch of sweetness.