Mary Randolph's Sweet Potato Pie

Cream butter in a mixing bowl; gradually add sugar, beating well. Add potatoes; beat at medium speed of electric mixer until well blended. Add eggs, one at a time, beating well after each addition.

Place brandy in a small pan; heat just until warm (do not boil). Add brandy, lemon rind, juice, vanilla, and nutmeg to sweet potato mixture; stir until well blended.

Pour mixture into pastry shell. Bake at 350° for 40 minutes or until a knife inserted in center comes out clean. Sprinkle pie with citron; cool completely.