Combine  pwd. sugar and peanut butter.  Put 1/2 of mixture in bottom of baked pie shell, reserving remainder.  In small bowl mix sugar, corn starch, flour and salt.  Blend in 1/4 c. milk and egg yolks.  Combine 1/3 C. sugar and 2 C. milk.  Bring to a boil and add yolk mixture.  Boil 4 min. or until thick.  Remove from heat and add vanilla, butter and an additional 1/4 C. (or more) peanut butter.  Cool.  Pour into pre-baked pie shell.  Spread Cool Whip over all.  Top with remaining powdered sugar/peanut butter mixture.  Sprinkle chopped peanuts on top if desired. 

-from Elaine Unruh