Preheat the oven to 400 F.
Put the sweet potatoes in a large mixing bowl and mash with a wooden spoon or a potato masher. Set aside.
Combine the eggs, sugar, spices, salt, lemon rind, and cream in a small bowl and whisk together until combined. Pour this mixture into the sweet potatoes and stir until thoroughly combined. Add the butter and mix well.
Pour into the pie crust and bake for 45 to 55 minutes, or until the filling is set and a knife inserted in the center comes out clean. Let cool completely before slicing.Servings: