Bake Potatoes: Heat oven to 400°F. Wash, poke, and bake sweet potatoes for 45 min or until soft. Cool completely.
Prep Crust: Bake pie crust for 15–20 min and set aside.
Make Filling: Scoop cooled sweet potatoes. Mix with butter until smooth. Add eggs, evaporated milk, sugar, vanilla, and pumpkin spice. Stir well.
Bake Pie: Pour filling into crust. Bake 50–60 min until a toothpick comes out clean. Cool, then refrigerate until fully cold.
Make Swiss Meringue: Whisk egg whites + sugar over a double boiler until sugar dissolves. Add cream of tartar halfway. Remove from heat, add vanilla, and whip 7–10 min until stiff peaks.
Finish: Spread or pipe meringue over the cold pie. Torch lightly if desired. Chill 1 hour before serving.
