French settlers brought the custom to Louisiana in the 18th century where it remained associated with the Epiphany until the 19th century when it became a more elaborate Mardi Gras custom. In New Orleans, the first cake of the season is served on January 6. A small ceramic figurine of a baby is hidden inside the cake, by tradition. However now, the tradition is giving way to the baby being supplied and the customer placing the baby were ever they wish in the cake. Whoever finds the baby is allowed to choose a mock court and host the next King Cake party the following week (weekly cake parties were held until Mardi Gras).
In 1870, the Twelfth Night Revelers held their ball, with a large king cake as the main attraction. Instead of choosing a sacred king to be sacrificed, the Twelfth Night Revelers used the bean in the cake to choose the queen of the ball. This tradition has carried on to this day, although the Twelfth Night Revelers now use a wooden replica of a large king cake. The ladies of the court pull open little drawers in the cake's lower layer which contain the silver and gold beans. Silver means you're on the court; gold is for the queen.
The classic king cake is oval-shaped, like the pattern of a racetrack. The dough is basic coffee-cake dough, sometimes laced with cinnamon, sometimes just plain. The dough is rolled out into a long tubular shape (not unlike a thin po-boy), then shaped into an oval. The ends are twisted together to complete the shape (HINT: if you want to find the piece with the baby, look for the twist in the oval where the two ends of the dough meet. That's where the baby is usually inserted.) The baby hidden in the cake speaks to the fact that the three Kings had a difficult time finding the Christ Child and of the fine gifts they brought.