You can make event food with them in the kitchen of your camp.
You find all information about this event here
Including cooking, event items etc.
There you can see that it‘s the pearls that you need for the event equipment. So as long as you want to buy some of those, don’t cook the recipe that needs the pearl. Cook only the one with oranges and sugar.
You find all wiki pages for events easily by google „Diggy name of event“.