Bake pastry shell.
Soften gelatin in cold water. Combine pumpkin, brown sugar, egg yolks, spices, and salt in top of double boiler; cook over hot, not boiling water until thickened, stirring constantly. Add softened gelatin to hot pumpkin mixture and stir until dissolved. R emove from hot water. Chill until it begins to thicken.
Beat egg whites until stiff but not dry; beat in granulated sugar. Fold into cooled pumpkin mixture, add orange rind.
Whip cream and fold into pumpkin mixture. Pour into baked shell; chill. Top with additional whipped cream.