Said to be the costliest of its kind in the world, a cronut (a croissant and donut hybrid) worth £1,500 (about $1,967) has gone on sale in London. The cronut is called the 'Luxury Zebra Cro'. It includes a gold leaf, Cristal rosé champagne caviar and Amedei Porcelana, often referred to as the most expensive chocolate in the world.