I went looking for definition of "cozy mystery" and all of them said that the violence and sex very common to hardcore mysteries are downplayed, vaguely described, or made humorous. Hot Chocolate meets those criteria though personally I'm not a fan of the comedic objectification of nurse Bambi's body and clothing. The problem is that when I amused while reading it wasn't laughing with the sisters or the situation, it was more of a uneasy laughter or simply discomfort at how characters were described.
Another criteria for "cozy mystery" is that the heroine, and it is always a heroine, is someone the reader needs to like especially when series are very common in the genre. Quirky describes the Alcotts well from their old-fashioned names, interfamilial oddities, candy and chocolate colored luxury cars, and what to me often seemed like outlandish fashion and lifestyles. But quirky isn't likeable and to be blunt, I didn't like any of the three sisters. Of the three -- Madge, Lila Mae, and Dorothea -- Lila Mae is the one who gets most "screen time" and she is the least likeable of all of them. Her life is driven by a belief in astrology and other new age or "ancient" beliefs yet she makes sudden decisions when she really should be holding steadfast to her proclaimed beliefs. Overall I found her rude and self-centered. Dorothea is also very self-centered though I felt something for her given that her father has been her primary responsibility; taking care of elderly, ill parents can be very draining. Madge, the eldest, is the most likeable but we really don't spend enough time with her.
Obviously a mystery needs to be central to any subgenre within that larger literary category of mystery. The mystery is usually a disappearance or death. In the "cozy mystery" it is not shown, merely referred to, though a body may be examined just not in graphic detail. As I kept reading the book, I kept looking for a mystery. Normally the mystery should be revealed by the end of chapter three... honestly that feel late to me but standard guidelines for mysteries give it up to chapter three for the murder to happen. Remember the focus is on the mystery, not on world building or funny interpersonal relationships, that would be a different genre of fiction. There is no mystery in this book until chapter 11... chapter 11, page 123 is where a body is found (I'm not going to reveal which character). In a "cozy mystery" the victim, either murdered or missing, has less than a sterling reputation in his or her community and the victim in Hot Chocolate fits that criteria to a tee.
A "cozy mystery" should really revolve around the sleuth's actions, thoughts, and relationships she has with the small community where the mystery must be solved. We see a lot of interactions between the characters, we spend a lot of time on individuals, too, looking at their homes, their clothes, digging into their thoughts but the focus should be on the mystery and solving it. In the "cozy mystery" the heroine generally has a romantic or at least deep friendship with someone who can give her information the case -- a coroner, a detective, a reporter, etc -- and Lila Mae is romantically involved with Police Detective Chance Walker indicating that Lila Mae, as unlikeable as she is, is our sleuth. Yet that isn't what happens. The story continues to bounce around from characters -- we follow Detective Walker, we follow Bambi, we follow Lila Mae, there is no central sleuth. Without a central viewpoint sleuth the story roams around, not focused on gathering clues trying to find the killer.
In any mystery subgenre, solving the mystery should rely upon the sleuth's logic, use of experts or her own expertise, and be realistic. Given the astrology focus of the book I was worried about this criteria because through chapter 11 I wasn't seeing much from the Alcotts that spoke to their abilities at all in the mental skills required to be a sleuth. I didn't have to worry so much about that because there was no sleuth to follow as she searched for clues, using her relationships and mental prowess to solve the case. When Lila Mae thinks she has it solved, it comes out of the blue because the plot hasn't focused on her gathering any evidence or making any observations until that moment in chapter 33 when she declares that she knows who the killer is. Of course, it can't be that straight forward in any mystery, there have to be red herrings but in the end Lila Mae didn't solve the mystery, the police did. To be blunt, this book would be much better at half the length and following Lila Mae as she does her cozy mystery solving.
Finally I want to mention the style of the writing. We are told a lot about each of the Alcott sisters in highly descriptive paragraphs that layout everything from their clothing and homes to their histories. Written in a third person narrative fashion that switches between the sisters and some other characters, the style of detailed telling is fairly common in many books I've sent to review. I can't say that I'm a fan because I was taught to show more than tell, to let the world and the characters come into focus through their actions and words. The details we get on characters varies as we might expect with the sisters the main characters they should be the most detailed but which other characters we are given details about their looks, their clothes, their backgrounds, their attitudes, that varies quite a bit. I was thinking there might be a trend but even by the end of the book I couldn't find a pattern to which characters are more detailed than others beyond the sisters. This isn't to say that we aren't shown the sisters and their world, we are, I just wanted more showing and less telling. But what do I know when so books are coming out like this over the past decade?
Sites Consulted for information about Mystery and Cozy Mystery genres:
Top Rules for Mystery Writing
Cozy Mystery List
Immense Popularity of Cozy Mysteries
Mystery Writing Basics -- Characters and Plot