In a bowl, combine powdered sugar and 2 tsp. Lavender; cover and set aside at room temp. for 24 hours.
In a mixing bowl, cream butter, sugar and remaining lavender.
Combine flour, cornstarch and salt; add to the creamed mixture. Divide dough in half. Cover and refrigerate for 2 hours or until easy to handle.
On a lightly floured surface, roll out one portion of dough to 1/4 inch thickness. Cut into 1 1/2 inch squares. Repeat with remaining dough.
Place 1 inch apart on ungreased baking sheets. Prick with a fork several times. Bake at 325º for 18-22 minutes or until edges are lightly browned. Cool for 1 minute before removing to wire racks to cool completely.
Sift reserved lavendar sugar; discard lavender. Dust cookies with sugar.
Store in airtight container.
Recipe submitted by florentine on 7/8/00