Bake empty pie shell according to directions.In a small bowl. place confectioner's sugar and peanut butter. Cut sugar into peanut butter with a fork until mixture is crumbly. Place half of mixture in bottom of baked pie shell, reserve remainder. In large sauce pot,place egg yolks, milk 2/3 cup sugar, vanilla, salt,and cornstarch. Cover over medium heat to medium low heat until thick,stirring constantly. Pour over peanut butter in pie crust.Beat egg whites until foamy, add sugar. Continue beating until soft peaks form. Spread over top pie, being careful to seal at edges. Sprinkle remainder of peanut butter crumbles over top of pie.
Bake at 325 for thirty minutes. Refrigerate for several hours before serving.