Press edible flowers between 2 pieces of wax paper and set a heavy book on top for at least an hour. Longer is better.
Carefully peel off the top layer of wax paper. Some of the petals will stick. You can try to salvage them or just use the ones that didn't stick.
Mix 1 teaspoon of meringue powder with 1 tablespoon powdered sugar and add a few drops of water until you have a paste. That will be your glue for the flower petals.
Paint a small amount of the paste on the back of the edible pressed flower and place on the cookie!