Wash and dry the sweet potatoes thoroughly.
Preheat your oven to 400°F (200°C). Line a baking sheet with foil or parchment paper.
Pierce each sweet potato several times with a fork to allow steam to escape.
Place the sweet potatoes on the prepared baking sheet and bake for 45-60 minutes, or until completely tender when pierced with a knife.
Allow the sweet potatoes to cool until you can handle them comfortably.
Peel away the skins and place the flesh in a large mixing bowl.
Mash the sweet potatoes thoroughly with a potato masher until no lumps remain.
Measure out 2 cups of the mashed sweet potato for your pie. Any extra can be saved for another use.
In a large bowl, combine the 2 cups of mashed sweet potatoes with the melted butter, mixing until well incorporated.
Add both the granulated and brown sugars and mix until the mixture is smooth and the sugars have dissolved.
In a separate small bowl, beat the eggs lightly.
Add the beaten eggs to the sweet potato mixture and stir until fully incorporated.
Pour in the evaporated milk and vanilla extract, stirring to combine.
Add all the spices and salt, mixing thoroughly to ensure even distribution.
Use a hand mixer or stand mixer on medium speed for about 2 minutes to create a smooth, lump-free filling. Alternatively, you can process the mixture in a food processor for the silkiest texture.
Remove your prepared pie crust from the refrigerator.
Pour the sweet potato filling into the unbaked pie crust, spreading it evenly with a spatula if needed.
Tap the filled pie plate gently on the counter a few times to remove any air bubbles.
Place the pie on the center rack of your preheated oven.
Bake for 45-55 minutes, or until the center is almost set. The pie is done when a knife inserted about 1 inch from the edge comes out clean. The center may still be slightly jiggly but will firm up as it cools.
If the crust begins to brown too quickly, cover the edges with aluminum foil or a pie crust shield.
Allow the pie to cool completely on a wire rack for at least 2 hours before slicing. The filling will continue to set as it cools.
Refrigerate for at least 4 hours (preferably overnight) for the best flavor and texture.