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 with weights. Bake for 15 minutes, then remove weights and bake for an additional 5 minutes until golden brown. Allow to cool slightly.

In a medium saucepan, combine whole milk and heavy cream with ground cinnamon and vanilla extract. Heat over medium until steaming, making sure not to boil. If using a whole cinnamon stick or vanilla bean, let steep for about 10 minutes.

In a mixing bowl, whisk together fresh eggs, granulated sugar, and a pinch of salt until pale and smooth, around 2-3 minutes.

Slowly pour the hot milk mixture into the egg mixture, whisking continuously. Strain through a fine-mesh sieve into a clean bowl.

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

Allow the pie to cool at room temperature for about 30 minutes. Cover with plastic wrap and refrigerate for at least 2 hours, or overnight.