Place gelatine in custard cup. Add cold water and let stand 2 minutes. Place custard cup in pan of boiling water until gelatine dissolves.

Add to jellied cranberry sauce (crushed with a fork) or whole cranberry sauce. Add salt, lemon rind and lemon juice; chill until mixture begins to set.

Beat egg whites until stiff and beat in sugar. Fold into cranberry mixture.

Pour filling into baked pastry shell and chill until firm. Top with whipped cream, if desired.