Preheat oven to 400°F. Wash and dry sweet potatoes, pierce each several times with a fork, then place directly on a foil-lined baking sheet.
Roast sweet potatoes for 45-60 minutes until a knife slides through the center with no resistance. Remove from oven and let cool until comfortable to handle.
Peel away the skins (they should slip off easily) and place flesh in a large mixing bowl. Mash with a potato masher or pass through a ricer until smooth. You should have about 2 to 2½ cups of mashed sweet potato.
Reduce oven temperature to 350°F. Add granulated sugar and brown sugar to the mashed sweet potato. Using a hand mixer or stand mixer, beat until smooth and creamy, scraping down sides as needed.
Pour in melted butter and evaporated milk, then mix until fully combined. Add eggs one at a time, beating well after each addition.
Mix in vanilla extract, cinnamon, nutmeg, ginger, cloves, and salt. Beat the filling for another minute until it looks silky with no lumps remaining.
Place unbaked pie crust into a 9 inch deep dish pie plate. Crimp the edges as desired. Pour sweet potato filling into the crust, spreading evenly with a spatula. Gently tap the pie plate on the counter a few times to release air bubbles.
Place pie on the middle rack of the oven. Bake at 350°F for 55-65 minutes. Check crust edges around the 30-minute mark and add a pie crust shield or foil if browning too quickly.
Pie is done when the center is set but still has a slight jiggle, similar to a baked custard. Remove from oven and place on a wire cooling rack. Let cool at room temperature for at least 2-3 hours to allow the custard to fully set.
Once fully cooled, slice with a clean, sharp knife for the neatest pieces. Serve with whipped cream, ice cream, or a dusting of cinnamon if desired.