Hi All-  I saw this technique mentioned in someone's blog but of course when I need it I can't find it. 

Anyway, how do you create the silver shimmering cookie?  I'm not talking about just adding corn syrup or painting on a sparkly dust.  This particular cookie blogger added the sparkling dust added to the royal icing.  Any ideas?  I need to make sure I use the correct edible dust too.

Thanks, Mary