*Melt chocolate and cool. In large mixing bowl, cream butter and sugar until fluffy. Blend in chocolate and 2 tsp. vanilla. Add eggs, two at a time, beating 5 minutes after each addition, or until sugar is dissolved and mixture is light and fluffy. Pour into cooled pie shell.Refrigerate for at least 2 hours, or until filling is firm. Whip cream with powdered sugar and 1 tsp.vanilla until stiff. Garnish pie with whipped cream and grated chocolate before serving.