Begin by peeling the sweet potatoes and cutting them into chunks. Boil them in a pot of water for about 15-20 minutes or until they are fork-tender. Drain the potatoes, then mash them until smooth. Set aside to cool slightly.
In a large mixing bowl, combine the mashed sweet potatoes, sweetened condensed milk, eggs, vanilla extract, cinnamon, nutmeg, ginger, and salt. Use an electric mixer or a whisk to blend everything until smooth and fully combined. The filling should have a velvety texture.
Preheat your oven to 350°F (175°C). Lightly grease the pie crust with butter to prevent the filling from sticking.
Pour the sweet potato filling into the prepared pie crust. Use a spatula to smooth out the top, making sure it’s evenly distributed.
Place the pie in the preheated oven and bake for 40-45 minutes, or until the filling is set and a knife inserted into the center comes out clean. The edges of the crust should be golden brown.
Remove the pie from the oven and let it cool to room temperature before slicing. This pie can be served immediately or chilled for a few hours for a firmer texture.