In a saucepan mix together sugar, cornstarch, and salt. Stir in the milk and bring to a boil over low heat. Cook until thickened, stir in the vanilla extract, butter and peanut butter. Let cool slightly, mix together on high speed in blender or with a plastic blade in a food processor. Pour into pie shells. Chill well.
To serve, top with fresh whipped cream.Makes 2 pies Source: