In Greece we traditionally have the Vassilopitta cake at New Year. A coin or special good luck charm called the floori is placed in it and whoever gets the slice with this in it supposedly has good luck all the year. Slices are not only cut for the people there, but also for the House, God, Christ and whoever else you wish. Obviously if God or Christ's slice has the coin or charm, it doesn't mean that they're going to have good luck (!) but that you will feel their influence all year.
There are different ways that people make Vassilopitta - probably as many as there are Greek grandmothers! - but this is one that we like. The photo is from last year's cake as you can see, this year's hasn't been made yet.