The Greek New Year's tradition involving a cake with a hidden coin is called vasilopita.
Vasilopita is a New Year's cake or bread prepared in Greece and in Greek communities around the world. A coin, traditionally called a flouri, is hidden inside before baking. At the New Year celebration, the cake is cut into portions, often beginning with symbolic slices for religious figures, the household, or the year itself, followed by slices for family and guests.
The person who finds the coin is believed to receive good luck for the coming year. Recipes vary considerably: some versions are sweet and cake-like, while others resemble enriched bread. Citrus flavoring, spices, and powdered sugar are common in many modern recipes.
The name refers to Saint Basil, or Agios Vasilios, whose feast day is celebrated in Greece on January 1. Vasilopita is therefore connected both to New Year's Day and to the saint's day. It is not the same as baklava, which is a layered pastry made with filo, nuts, and syrup.