Place cornstarch in mixing bowl. Stir to eliminate any clumps. Add remaining ingredients except frosting. Beat on low speed, scraping sides of bowl often, until mixture changes from coarse crumbs to stiff dough. This may take up to five minutes of beating. With your hands, shape half dough into 1-inch roll about eight inches long. Wrap in plastic wrap. repeat with other half of dough. Refrigerate until firm, one to two hours.

When ready to bake, preheat oven to 350-degrees.

To form cookies, use a sharp knife and slice dough into 1/4-inch rounds. Place about 1-inch apart on ungreased cookie sheets. Bake in preheated oven about 12 minutes; watch carefully so cookies do not brown. Cookies are crumbly. Handle carefully when removing from pan to cool and while frosting.

Prepare frosting. Frost cookies and store in layers between plastic wrap in sealed tins. Refrigerate or freeze for serving later.