Preheat the oven to 375°F (190°C). Roll out your pie crust into a 9-inch pie dish, line with parchment and fill with weights. Bake for 15 minutes, then remove weights. Bake for another 5 minutes until golden.

Heat whole milk, heavy cream, ground cinnamon, and vanilla extract in a saucepan over medium heat until steaming, about 5 minutes.

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

Slowly pour hot milk mixture into the egg mixture while whisking to temper. Strain custard through a fine sieve into a clean bowl.

Reduce oven temperature to 325°F (160°C). Pour custard into the cooled crust and bake for 35-40 minutes, until edges are set.

Cool at room temperature for at least 30 minutes, then refrigerate for a minimum of 2 hours before slicing.