In a medium bowl, combine the butter, shortening, flour, and salt. Blend until the mixture resembles coarse crumbs.

Sprinkle cold water over the mixture and stir with a fork until the dough comes together.

Form the dough into a ball, flatten into a disk, wrap in plastic, and refrigerate for 20 minutes.

Preheat your oven to 400°F while the dough chills.

In a separate bowl, whisk together the filling ingredients until smooth and well combined.

Flour your work surface and roll out the chilled dough to a rough 9-inch circle.

Use a 4-inch cookie cutter to cut out 10 rounds from the dough.

Press each round into the muffin pan cups, fluting the edges if desired.

Fill each crust with the pumpkin filling mixture.

Bake for 10 minutes at 400°F, then reduce the temperature to 325°F and bake for an additional 10 minutes.

Let the mini pies cool in the pan before carefully removing them.

Serve the pies with a dollop of freshly whipped cream.