Preheat your oven to 350°F (175°C).

Roll out the pre-made pie crust and place it in a 9-inch pie dish. Pinch the edges to create a decorative border. If desired, line the crust with parchment paper and fill it with pie weights or dried beans to prevent bubbling. Bake for 10 minutes. Remove weights and parchment, and bake for an additional 5 minutes until lightly golden. Remove from oven and set aside to cool.

In a mixing bowl, whisk together the eggs and granulated sugar until well combined and slightly frothy.

In a saucepan over medium heat, combine the heavy cream, whole milk, vanilla extract, ground cinnamon, salt, and cornstarch. Whisk continuously until the mixture is heated through but not boiling.

Gradually pour the hot cream mixture into the egg and sugar mixture, whisking constantly to temper the eggs. Ensure the eggs do not scramble.

Once combined, pour the custard filling into the baked pie crust. Smooth the top with a spatula.

Bake in the preheated oven for 30 minutes, or until the custard is set and has a slight jiggle in the center.

Remove the pie from the oven and allow it to cool at room temperature for at least 1 hour. Once cooled, refrigerate for at least 2 hours before serving.

Slice and serve chilled, garnished with a sprinkle of cinnamon or whipped cream if desired.