Preheat your oven to 375°F (190°C). Roll out your pie crust and fit into a 9-inch pie dish. Line with parchment paper and fill with weights. Bake for 15 minutes, remove weights, bake for 5 more minutes until golden brown. Let cool slightly.

In a medium saucepan, combine whole milk, heavy cream, ground cinnamon, and vanilla extract. Heat over medium-low until steaming. If using a stick, steep it in the mixture, then remove.

In a large bowl, whisk together eggs, sugar, and salt until pale and smooth, about 2-3 minutes.

Gradually pour hot cream mixture into eggs while whisking continuously to prevent curdling. Strain through a fine mesh sieve into another bowl.

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

Allow pie to cool at room temperature for at least 30 minutes. Chill in refrigerator for at least 2 hours before serving.