Drain pineapple and save juice.  Mix pineapple and marshmallows together and set aside.

In a saucepan, combine juice, flour, sugar, egg, and vinegar. Cook until slightly thickened.  When mixture is cold combine with Cool Whip.  Fold in marshmallow mixture.  Add apples and peanuts.  Sprinkle top with extra nuts. 

Most nuts go in the salad but save some for the top.