By | May 29 2012 12:39 PM

New York City restaurant Serendipity 3 already makes the world's most expensive sundae -- that would be the $1,000 Golden Opulence Sundae -- but the Upper East Side eatery can now also claim the world's most expensive hamburger, too. On May 22, Serendipity 3 set the Guinness World Record for the world's most expensive hamburger with its Le Burger Extravagant, a sandwich that will set you back $295, and likely several hundred calories.