The world's most expensive cake is a gem- encrusted birthday and engagement dessert that is six foot long, includes 4,000 real diamonds and was created by a top fashion designer, 33 year old mother of 3, Debbie Wingham, who turned to baking after creating the world's most expensive dress for £11.5million from black and red diamonds. She spent 1,100 hours on her latest masterpiece which she made for a rich Arab family living in the United Arab Emirates. The cake cost $75 million! The cake includes amethysts and emeralds. It also has a runway with models strutting on the runway. Figures on the cake have designer handbags, dark glasses and footwear as well as the latest electronic devices. The cake weighed 450kg....that's a massive cake!