Guido Castagna is a renowned chocolatier from Turin, Italy, known for his expertise in creating high-quality gianduia chocolates. His chocolate shop, founded in 2002, has quickly become one of the most esteemed in Turin due to its focus on natural ingredients and artisanal methods.

Castagna's signature product, the Giuinott, is celebrated for its blend of cocoa and hazelnuts, earning multiple awards at international competitions. His shop also offers a variety of other chocolate products, including truffles and spreadable gianduia.