Preheat your oven to 350°F (175°C).

Prepare the pie crust by fitting it into a 9-inch pie dish.

In a medium saucepan over medium heat, combine cranberries and 1/2 cup of sugar; cook until cranberries burst.

In a large bowl, whisk together the eggs, remaining sugar, milk, vanilla extract, cornstarch, and salt.

Fold in the cooked cranberries into the custard mixture.

Pour the custard filling into the prepared pie crust.

Bake in the preheated oven for 40-50 minutes, until the custard is set.

Allow the pie to cool completely before slicing.

Serve chilled, optionally garnished with whipped cream.