Prepare pastry for a filled one crust pie using a 9 inch pie pan.
Heat oven to 350 degrees F. In a small bowl, beat egg whites until stiff peaks form. In large bowl, beat egg yolks and brown sugar until mixture is light in color and thickened. Blend in peanut butter and corn syrup. Gradually beat in milk and vanilla. Fold egg whites into peanut butter mixture. Pour into pastry line pan.
Bake at 350 degrees F. for 30 to 35 minutes or until filling is set. Serve warm or at room temperature. Store in refrigerator.