Melt-in-your-Mouth Shortbread

[from _The Food Allergy Cookbook_]

1/2 cup cornstarch
1/2 cup icing [confectioner's] sugar
1 cup rice flour
3/4 cup butter

Sift cornstarch, sugar and rice flour together. Add butter. 
Mix with hands until soft dough forms. Refrigerate one hour.
Shape dough into 1" balls. Place about 1-1/4 inches apart on
greased cookie sheet; flatten with lightly floured fork. Bake at 
300 (F) [150 (C)] for 20-25 minutes or until edges are lightly

Form balls as above. Roll in finely crushed corn flakes or
crushed nuts. Press top of ball with thumb. Add a dab of jelly.

Mix in 2 tbls. finely chopped peel and/or 2 tbls. finely 
chopped nuts. Flatten with lightly floured fork.