Well, is it?

Super-niche single-item restaurants are nothing new in these parts — like This Little Piggy Had Roast Beef, the Meatball Shop, and Rice to Riches — but the Best Chocolate Cake in the World just might take the award for sheer chutzpah in naming. We walked past its tiny Nolita storefront last weekend, and wondered where it gets off being so cocky. This is the first American outlet of a São Paolo, Brazil-based mini-chain (where it goes by the similarly direct name O Melhor Bolo de Chocolate de Mundo); chef Carlos Bras Lopes’s hopes his cake recipe, which he brought to Brazil after emigrating from Portugal, will enrapture New Yorkers just as much as it has South Americans when it opens this week.

Per the official website (with thanks to Google Translate and a Portuguese-speaking friend of Grub Street), Bras’s “best chocolate cake in the world” is actually three cakes of varying sweetness: a sugary cake made with 53 percent cocoa, a semisweet made with 70 percent, and — for those adventurous of palate — a bitter, zero-sugar version that’s touted as being lower in calories. All are variations on a recipe made “without flour or baking powder … a confection made from a top-of-the-line Belgian chocolate mousse,” which from pictures appears to be swirled together with meringue. In Brazil, you can get your slice of cake with a glass of port, but according to Time Out, the American iteration will offer Counter Culture coffee and cold treats from Il Laboratorio del Gelato.

The Best Chocolate Cake in the World, 55A Spring St., nr. Mulberry St.; 212-343-2253