In a large bowl, mix all-purpose flour and a pinch of salt, then cut in cold butter and shortening until the mixture resembles coarse crumbs. Gradually add ice water, mixing until dough forms. Roll out the dough on a floured surface and fit it into a 9-inch pie dish, gently pressing the sides and trimming the excess.

Preheat your oven to 375°F (190°C). Lining the crust with parchment, fill it with pie weights or dried beans, and place it in the preheated oven for about 10-15 minutes until set.

In a large mixing bowl, whisk together pumpkin puree, granulated sugar, brown sugar, and spices. Add in well-beaten eggs, heavy cream, and cornstarch, whisking until smooth.

Once the crust has cooled slightly, remove the parchment and weights. Pour the smooth pumpkin filling into the pre-baked crust.

Bake for 55-60 minutes at 350°F (175°C) until filling is set around the edges but slightly wobbly in the center.

Let the pie cool completely to room temperature for at least 4 hours. Serve with dollops of whipped cream and optional sugared cranberries.