Preheat oven to 350°F (175°C). Place the chilled unbaked 9-inch pie crust on a baking sheet lined with parchment paper.
In a large mixing bowl, beat the warm roasted sweet potato flesh with softened butter using an electric hand mixer on medium speed for 2 minutes until completely smooth and lump-free.
Add the granulated sugar, light brown sugar, and evaporated milk. Beat on low speed until combined, then increase to medium until the sugars dissolve into a silky emulsion.
Add the beaten eggs, pure vanilla extract, ground cinnamon, freshly grated nutmeg, ground ginger, and sea salt. Beat on low speed just until fully incorporated and velvety.
Pour the smooth sweet potato custard filling into the unbaked pie crust, smoothing the top with an offset spatula.
Bake at 350°F (175°C) on the lower-middle oven rack for 50 to 55 minutes, until the edges are puffed and set and the center has a gentle, subtle jiggle when shaken.
Transfer to a wire cooling rack and allow the pie to cool completely at room temperature for at least 2 hours to fully set into silky custard perfection. Slice and serve with a dollop of whipped cream!