Lemon shortbread cookies

Preheat oven to 350 degrees.
In a large mixing bowl of an electric beater, combine flour, cornstarch, powdered sugar, butter, lemon peel and lemon juice.
Beat at low speed, scraping bowl often, until well mixed (2 to 3 minutes.) Shape the dough into a 14 by 1-inch cylinder.
Roll in the remaining 2 tablespoons sugar. Wrap in plastic food wrap. Refrigerate until firm.
With a sharp knife, cut the log into 1/4-inch thick slices. Place one inch apart on cookie sheets.
Bake for 10 to 12 minutes or until set. (Cookies will not brown.) Cool on racks. Store in an airtight container.