Bake the sweet potatoes at 400°F for 50 to 60 minutes until completely soft, then cool, peel, and measure 2 cups flesh.
Lower the oven to 350°F and set the crust on a rimmed sheet pan.
Beat the sweet potato, brown sugar and butter until smooth, then mix in the eggs one at a time.
Add the evaporated milk, cinnamon, ginger, nutmeg, vanilla and salt and mix only until uniform.
Pour into the crust and bake for 50 to 55 minutes until the edges are set and the center wobbles slightly.
Cool for 3 hours before slicing.