Preheat the oven to 375°F (190°C).
Prepare the pie crust according to package instructions or your favorite recipe.
In a mixing bowl, combine the eggs and sugar, whisking until well combined.
Add the heavy cream, vanilla extract, cinnamon, and salt to the egg mixture, whisking until smooth.
Fold in the cranberries gently, ensuring they are evenly distributed throughout the custard mixture.
Pour the custard mixture into the prepared pie crust, spreading it evenly.
Bake the pie in the preheated oven for 40-45 minutes, or until the custard is set and lightly golden.
Remove the pie from the oven and allow it to cool at room temperature for at least 2 hours.
Serve slices at room temperature or chilled, garnished with whipped cream if desired.