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 and fill with pie weights. Bake for 15 minutes, then remove weights and bake for an additional 5 minutes until golden brown. Cool.

In a medium saucepan, combine whole milk, heavy cream, ground cinnamon, and pure vanilla extract. Heat over medium until steaming but not boiling. If using a cinnamon stick, steep it for flavor.

In a mixing bowl, whisk together the eggs, granulated sugar, and salt until pale and smooth, about 3-4 minutes.

Slowly pour warm milk mixture into egg mixture while whisking to temper the eggs. Strain through a fine mesh sieve into a clean bowl.

Lower oven temperature to 325°F (160°C). Pour custard into pre-baked crust. Bake for 35-40 minutes until edges are set and center jiggles slightly.

Cool pie at room temperature for 30 minutes, then refrigerate for at least 2 hours or overnight before serving.