To make Rose Shortbread, use 1 Tbsp. crushed rose petals and 2 tsp. rose water in place of lavender flowers and lavender extract.
Whip butter with an electric mixer until fluffy, about 5 min. Stir in lavender extract, powdered sugar, cornstarch and flour, and beat on low for 1 min., then on high for 3 to 4 min. Stir in lavender flowers. Drop cookies by heaping teaspoons about 2 inches apart on an ungreased cookie sheet. Bake for 10 to 13 min., watching that the edges don't brown too much. Cool cookies on wire racks.
Elizabeth Bannas, Savory Spice Shop—Portland, OR customer