Preheat your oven to 350°F (175°C).

Place the sweet potatoes in a large pot of water. Bring to a boil and cook until tender, about 40-50 minutes. Alternatively, bake the sweet potatoes in the oven at 400°F (200°C) for about 1 hour, or until soft.

Once cooked, drain and allow the sweet potatoes to cool slightly. Peel the skin off and mash the sweet potatoes in a large mixing bowl until smooth.

Add the softened butter to the mashed sweet potatoes and mix until the butter is fully melted and incorporated.

Stir in the granulated sugar and brown sugar until well combined.

Add the eggs one at a time, beating well after each addition.

Pour in the evaporated milk, vanilla extract, cinnamon, nutmeg, ginger, and salt. Mix until the filling is smooth and all ingredients are well combined.

Pour the sweet potato filling into the thawed premade pie crust, spreading it evenly with a spatula.

Place the pie on a baking sheet to catch any spills and bake in the preheated oven for 55-60 minutes, or until the filling is set and a toothpick inserted into the center comes out clean. If the edges of the crust start to brown too quickly, cover them with aluminum foil or a pie crust shield to prevent burning.

Remove the pie from the oven and allow it to cool completely on a wire rack before serving. Serve the pie at room temperature or chilled, with a dollop of whipped cream if desired.