From Goodreads:

Stan Kraychik #2

Valentine's Day is fast approaching and everyone has a sweetheart, except Stan Kraychik, Boston's sassiest hairdresser. Ever hopeful of meeting Mr. Right, Stan attends a gala reception that culminates in a death by poisoning, and romantic problems take a back seat to murder.

The Boston police arrest Stan's friend Laurett Cole, who then leaves her four-year-old son in Stan's care. In his quest to free Laurett from suspicion and himself from his ill-mannered ward, Stan finds himself exploring the secrets of a revered Boston institution, the Gladys Gardner Chocolate Company. There, along with the sweet edibles, he finds an assortment of not-so-delectable murder.