Preheat oven to 425°F (220°C)
Prepare pie crust and fit into a 9-inch pie plate; crimp edges
Bake crust for 8–10 minutes (optional for extra crispness); set aside
Reduce oven to 350°F (175°C)
Roast sweet potatoes: pierce 3 medium sweet potatoes, bake 35–45 minutes until very tender, cool slightly, peel, and mash
In a large bowl, mix mashed sweet potatoes with:
3/4 cup brown sugar
1/2 cup evaporated milk (or use regular milk)
2 large eggs
1/4 cup melted butter (or 1/4 cup oil)
1 tsp vanilla extract
1 1/2 tsp ground cinnamon
1/2 tsp ground ginger (optional)
1/4 tsp ground nutmeg (optional)
1/4 tsp salt
Stir until smooth and well combined
Pour filling into prepared crust
Bake 45–55 minutes, until the center is set but still slightly jiggly
Cool on a wire rack 1–2 hours
Chill at least 2 hours before slicing (optional but recommended)
Serve chilled or at room temperature