Ingredients
Equipment
Method
- Heat the oven to 375 F. Scrub the sweet potatoes, prick each one several times with a fork, and set them directly on a rimmed baking sheet.
- Roast 50 to 60 minutes, until the skins wrinkle and a knife slides through the center with no resistance. Syrup bubbling from the fork holes is the sign you want. Do not boil them, water dilutes the flavor and loosens the custard.
- While the potatoes roast, fit the chilled crust into a 9 inch pie plate. Trim the overhang to about half an inch, fold it under, and crimp the edge. Chill the shell in the refrigerator until you are ready to fill it. There is no top crust on this pie.
- Split the hot potatoes and scoop the flesh into a mixing bowl, discarding the skins. You want about 2 packed cups. Add the softened butter and the salt and mash while everything is still hot so the butter melts in completely.
- Beat the potato mixture with an electric mixer on medium for 2 full minutes, until no fibrous strands remain and the mash looks whipped and glossy. For an especially silky pie, press it through a fine mesh sieve.
- Add the brown sugar and granulated sugar and beat 1 minute more. Beat in the eggs one at a time, then the evaporated milk, vanilla, cinnamon, nutmeg and ginger. The filling should be loose, pourable and the color of caramel.
- Raise the oven to 400 F. Pour the filling into the chilled crust and smooth the top, leaving about a quarter inch below the rim.
- Bake at 400 F for 15 minutes to set the crust, then lower the heat to 350 F without opening the door and bake 35 to 45 minutes longer.
- The pie is done when the outer 2 inches are set and puffed and the center still has a faint jiggle when you nudge the plate. A knife slipped in an inch from the edge should come out clean. Tent the crust edge with foil if it browns too fast.
- Cool on a wire rack for at least 3 hours. The custard firms as it cools, and cutting warm pie gives you a loose slice. Serve at room temperature or lightly chilled.
