Hey Marissa,
From the picture it looks like gold dust may have been sprinkled on the wet royal icing. But you have to be careful with that since all sparkly dust not edible. A lot of them say non toxic but you still should not ingest that.
Also just a tip since you are new to cookies. I would outline and flood the top of the cap first and get your gold look. You could always airbrush it gold. That is edible. It will look metallic not sparkly. Another option is may try putting clear sanding sugar in your wet royal icing and then airbrush it gold.
After you get the cap colored with your gold effect and it has completely dried (about a day) you can outline and flood the bottom of the cookie. Since the tussle isn’t touching the bottom of the hat you can pipe that as well. When everything is dry you can pipe the string.
Not sure if you wanted that much instructions but figured can’t hurt to help 😀. Hope that helps and would love to see your results.
