Using an electric mixer, combine cream cheese, sugar, cream, vanilla, and peanut butter. Chill a small bowl and beaters in the freezer. Whip the cream until very stiff in the chilled bowl. Add one-third of the whipped cream to the peanut butter mixture and fold into remaining whipped cream. Spoon into the chocolate pie crust or graham cracker crust.   Keep the pie refrigerated until you are ready to serve, and store the pie in the refrigerator.