Milne (The Nine Lessons
) slightly dials down his trademark oversentimentality in this serviceable novel of uplift. Chocolatier Sophie Jones carries around much guilt about her parents' accidental death when she was nine, so when her fiancé, Garrett Black, dumps her, she gets to feeling very, very sad. But in a lemons/lemonade moment, she channels her disappointment into a signature cookie: the Misfortune Cookie, which becomes a hit with her customers. She's eventually somewhat content, but then Garrett begs her to take him back, and she presents him with a challenge: prove that true happiness exists. The challenge, while silly, predictably leads them down a path they never expected. While this packs all the warm fuzzies Milne's readers would expect, a flood of too-serendipitous developments strain credibility, even for a cute, disposable confection. For readers willing to do some serious suspending of disbelief, there'll be some smiles. (June)