The cakes, which symbolize the crowns worn by the Three Kings (or Wise Men) on their visit to baby Jesus, traditionally contain a little figurine for children as well as a dry fava bean.
Whoever finds the toy is crowned king or queen of the celebration, while the one who finds the bean has to buy the Roscón next year.
But this year, El Corte Inglés has promised an even greater prize. The Spanish department store says it has hidden one gram gold ingots in 1000 of its cakes sold in the run up to Epiphany, each ingot with an estimated value of €47.
It has also included three special prizes of a gold ingot weighing an ounce with a value of €1,100.
El Corte Inglés expects to sell an estimated 600,000 roscones at its stores across Spain this year, in 25 different varieties.
But the department store isn't the only merchant to offer the promise of riches with each bite of cake.
A patisserie in León has hidden a prize worth €9,000 in one of its roscónes this year.
Manuel Antonio González, owner of the more than 150-year-old Conrado bakery in León said the prize would be hidden within a cake sold between now and Saturday and that they can be bought online too.
Meanwhile in Asturias, bakery chain Panris has hidden 14 prizes within its roscones; thirteen with a value of €100 and one cake containing a top prize of €1,000.
The traditional sweet dough of a Roscón is scented with orange blossom and can be served with cream but is best when dunked into steaming mug of rich hot chocolate after an evening watching the Cabalgata – the lavish parades held across Spain on January 5th when the Three Kings distribute sweets and presents to children.