Prepare and refrigerate the uncooked vegan pie crust while making the filling.
Preheat oven to 350°F (175°C). Peel and chop sweet potatoes, boil until fork-tender (12–15 minutes), then drain.
Mash sweet potatoes until smooth. Add coconut milk, brown sugar, vanilla, spices, salt, and cornstarch. Beat until fully combined.
Spread the filling evenly into the pie crust.
Bake for 55–60 minutes. Cover crust edges with foil if browning too quickly.
Let the pie cool on a rack for 1 hour before slicing.
Serve with vegan whipped cream, if desired. Store leftovers in the fridge for up to 5 days.