It is a tradition in Greece to eat a cake with a hidden treasure (in our case, a quarter) on New Year's Day. The person who finds the treasure will have good luck for the coming year. For more information about the tradition, Wikipedia is a pretty good source: http://en.wikipedia.org/wiki/Vasilopita
My grandmother made a cake this way (a yogurt cake, kind of like a really awesome poundcake), although if you go to Athens and look for "Vasilopita" (New Year's Cake, named for St. Basil), you will get something much closer to an egg bread.
Mine is from an old Greek cookbook my mother had, although I believe there is a modification or two she's made over the years. My father says this is just like his mother made.
It's a treat for New Year's Day, but also makes an excellent breakfast anytime.