Preheat oven to 375ºF. In a bowl, whisk together the brown sugar, cornstarch and salt. Add the pumpkin, eggs, cream and milk and whisk to combine. Pour the filling into a deep dish pie crust and bake until the center is set, 60 to 65 minutes, covering the edges of the crust with aluminum foil after 30 minutes if they brown too quickly. Transfer the pie to a wire rack and let cool completely, at least 2 hours, before serving.