Preheat the oven to 350°F (175°C) to prepare for baking the pie.
Fit the pre-made pie crust into a pie dish, prick the bottom and sides with a fork, and pre-bake for approximately 10 minutes. Allow to cool slightly.
In a large mixing bowl, combine the heavy cream and sweetened condensed milk, whisking until smooth.
Add the eggs, pure vanilla extract, ground cinnamon, freshly grated nutmeg, granulated sugar, and cornstarch to the cream mixture, whisking until fully integrated.
Pour the filling into the prepared pie crust, smoothing the surface with a spatula.
Bake for 25-30 minutes until the filling is set with a lightly golden top and a slight jiggle in the center.
Let the pie cool completely at room temperature, then refrigerate for at least 2 hours until chilled and firm.
Top with whipped cream and a dusting of ground cinnamon before serving.
Notes
Serve chilled with whipped cream and a sprinkle of cinnamon.