For a fun trick, I made the sprinkles out of glue. I spread a small line of the Multi Medium Matte glue on the frosting, and then sprinkled it with a fine white glitter. The glue dried and created a solid little sprinkle. It turned out so cute!
To add interest to the background panel, I created stripes with solid cardstock. The black and white stripes felt like a Sweet Shop to me. Exactly what I was hoping for.