Preheat your oven to 375°F (190°C). Roll out your pie crust and fit it into a 9-inch pie dish. Line the crust with parchment paper and fill it with pie weights or dried beans. Bake for 15 minutes until slightly firm. Remove the weights and parchment, then bake for an additional 5 minutes until lightly golden. Allow to cool slightly.

In a medium saucepan over medium heat, combine whole milk and heavy cream with ground cinnamon and pure vanilla extract. Heat until steaming, avoiding boiling. Remove cinnamon sticks if used, and let cool slightly.

In a large mixing bowl, whisk together eggs, granulated sugar, and salt until smooth and pale. This mix is essential for creamy custard filling.

Gradually pour warm milk and cream mixture into the egg mixture, whisking constantly to temper the eggs and prevent scrambling. Pour through a fine-mesh sieve for ultra-smooth texture.

Reduce the oven temperature to 325°F (160°C). Pour the custard into the pre-baked pie crust and bake for 35 to 40 minutes until edges are set and center jiggles slightly when shaken.

Allow the pie to cool at room temperature for about 30 minutes. Then refrigerate for at least 2 hours before slicing.