Preheat the oven to 350°F (175°C). Fit the pie crust into a 9-inch pie dish and crimp the edges. Prick the bottom with a fork to prevent bubbling.

Bake the pie crust in the preheated oven for 10 minutes until lightly golden. Remove and set aside to cool.

In a saucepan over medium heat, combine the whole milk and heavy cream. Heat until just simmering, then remove from heat.

In a mixing bowl, whisk together the sugar, eggs, vanilla extract, ground cinnamon, and salt until well combined.

Slowly pour the hot milk mixture into the egg mixture, whisking constantly to temper the eggs. Strain the mixture through a fine sieve into a clean bowl.

Pour the custard filling into the pre-baked pie crust. Bake in the oven for 30-35 minutes, or until the custard is set but still slightly jiggly in the center.

Remove from the oven and let cool to room temperature, then refrigerate for at least 2 hours before serving.

Top each slice with whipped cream and a dusting of ground cinnamon before serving.