Preheat oven to 350°F.

Lightly dust a large cutting board or flat surface with flour. Roll out a room temperature pie crust sheet so that it becomes thin enough to cut off about 30%, resulting in a final crust of 5 oz.

Place the thinned crust into a 9-inch pie dish, cutting off excess dough.

In a large bowl, combine pumpkin puree and softened butter. Mix well.

Using an electric mixer, mix in brown sugar, milk, eggs, egg whites, pumpkin pie spice, cinnamon, nutmeg, and vanilla. Beat on medium speed until the mixture is smooth.

Pour the filling into the unbaked pie crust. Bake for about 70 to 75 minutes, or until a knife inserted into the center comes out clean.

Cut into 10 slices and serve with whipped coconut cream or whipped cream if desired.