Preheat your oven to 375°F (190°C). Roll out your pie crust and place it in a 9-inch pie dish. Line with parchment and fill with weights. Bake for 15 minutes, then remove weights and parchment, baking for an additional 5 minutes until golden. Cool completely.

In a medium saucepan, combine the whole milk, heavy cream, ground cinnamon, and pure vanilla extract. Warm until steaming, without boiling. If using a cinnamon stick or vanilla bean, steep for 10 minutes.

In a large mixing bowl, crack the eggs and add granulated sugar and a pinch of salt. Whisk until pale and smooth, about 2-3 minutes.

Slowly pour the hot milk mixture into the egg mixture while whisking continuously. Strain the mixture through a fine-mesh sieve to ensure a smooth custard.

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

Allow the pie to cool to room temperature for about an hour, then refrigerate for at least 2 hours before serving.