A slave dessert
The origin of this tradition would seem to coincide with the celebration of the Saturnalia festivals in ancient Rome. These celebrations took place in the period equivalent to our month of January, when round cakes were made with figs, dates and honey and were distributed to both commoners and slaves. Since the 3rd century, one bean was included in the cake and whoever found it was named "king of kings" while the festivities lasted.
The current recipe
The chronicles speak of of different types of sweets in Navarra and Andalusia, probably inherited from the Romans, but the current recipe is due to the chef of Slavic origin from the court of the French King Louis XV.
During the Epiphany feast, the chef wanted to treat the sovereign with a dry sweet in the shape of a crown, inside which he hid a diamond necklace. The Spanish King Felipe V, a relative of the French sovereign, who was present on that occasion, was so delighted with the dessert that he asked for the recipe and brought it to Spain.
With cream and fruits?
The original recipe that Felipe V liked so much did not contain cream or any other addition. It was a dry bun sprinkled with some sugar. Candied fruits began to be added in the late 19th century, and the use of cream did not become widespread until the 1960s.
In what other countries do you eat Roscón de Reyes?
The Spanish have exported the roscón to the countries of Latin America, and it has become especially popular in Mexico and Colombia. All the same, in some European countries there are other vaguely similar desserts that are also eaten on these dates.
In France there is the Galette de Rois, which is a puff pastry filled with almond cream. And in Italy they eat the Fugassa de la Befana which, unlike the roscón, has no hole in the centre and is filled with “panna” instead of cream.