Heat oven to 425°F. Make pie crust as directed on box for One-Crust Filled Pie using 9-inch glass pie pan.
Place sweet potatoes, brown sugar, cinnamon, allspice, half-and-half, sherry and eggs in blender container or food processor bowl with metal blade. Cover and blend until smooth. Pour into pie crust-lined pan.
Bake 15 minutes. Reduce oven temperature to 350°F; bake 30 to 40 minutes longer or until center is set. Cool completely, about 45 minutes. Serve topped with whipped cream. Store in refrigerator.