Step 1

Preheat the oven to 400º degrees Fahrenheit (200°C). Wash the sweet potatoes and prick them 4 to 5 times with a fork. Bake on a baking sheet for 45 to 50 minutes, until tender and soft.

Step 2

Remove the sweet potatoes from the oven. When they’re cool enough to be handled, peel the skin off and mash, then leave to cool.

Step 3

Reduce the oven temperature to 350º degrees Fahrenheit (175°C).

Step 4

Prepare the crust: sift the flour and salt into a medium-sized bowl. Use a fork or a pastry blender to cut the shortening into the flour.

Step 5

Once it resembles coarse crumbs, gradually add the ice water, stirring with a fork until the mixture clumps together. (Add the water one teaspoon at a time).

Step 6

Remove the dough from the bowl and press it into a thick disk. Wrap the dough in plastic wrap and refrigerate for 10-30 minutes.

Step 7

On a lightly floured surface, roll the dough into a 13-inch circle, about 1/8-inch thick.

Step 8

Loosely roll the dough onto the rolling pin, lift it over a 9-inch pie dish, and gently unroll the dough to fit the pan. Carefully press the dough into the pan, then trim off any excess.

Step 9

Sprinkle ¼ cup brown sugar onto the crust, place in the oven, and bake for about 10 to 15 minutes (or until it's light golden brown).

Step 10

Mash sweet potatoes and butter until smooth and lump-free. Then add the sugars and mix until well combined.

Step 11

Whisk the half u0026amp; half, eggs, cinnamon, and nutmeg in a separate bowl until blended, then whisk into the filling mixture.

Step 12

Strain the filling and pour it into the partially baked pie crust.

Step 13

Bake the pie until a knife inserted in the center comes out clean - about 90 minutes.

Step 14

Cool completely on a wire rack. Cover and refrigerate until ready to serve with whipped cream.