I had a further idea - by this point in the future, stories and customs have got mixed up a bit, and so now Barrayar has the Festival of the Egg.

Children paint eggs and hide them around, to distract the Evil Voldemort from catching children and eating their souls. On the day of the festival it isn't safe to say his name, else you attract his attention. At midnight when it's deemed safe, there are fireworks (because it's Barrayar, of course there are fireworks.) In the morning, the children go out to find any eggs Voldemort missed and discover they've been turned into fake eggs that are hollow, with tiny gifts inside.

(The poor parent who has to stay up past the fireworks and replace all these eggs... Maybe children aren't allowed to go hunt eggs until noon.)