In a bowl, beat the cream cheese with the confectioners' sugar until light and fluffy. Beat in the milk, peanut butter and vanilla.

In a chilled bowl, beat the heavy cream until stiff. Stir one-third of it into the peanut butter mixture. Then fold in the remaining cream gently, but thoroughly.

Turn the filling into the baked pie shell. Sprinkle with chopped peanuts. Chill the pie, covered, for at least 4 hours.