Even "Cozy" mysteries include evil. Although Aunt Dimity manages to avoid murder, blackmail, theft, missing persons, mean rumors, loud and obstreperous new neighbors, sinister strangers, missing or lost items of great value, ancient documents that tell of treasure and/or heartache, (I know that's an odd combination. Read Aunt Dimity for any explanations.), can offer a LOT of coziness.
Most cozy mysteries do deal with murder, (sigh). I have spent a lot of time with Patricia Wentworth, Ngaio Marsh and their ilk lately. Alan Bradley and his preteen sleuth, Flavia de Luce, are favorites as well.
Picking up a new writer - Donna Andrews - I think I have found a series I can follow.
I also believe I have deciphered the ingredients for a popular "cozy" mystery series:
SIX INGREDIENTS FOR A COZY MYSTERY
1. Quaint, charming, odd or intriguing setting. A large family compound with forests nearby, a houseboat, a moldering family estate, a cottage in a secluded and eccentric village, a library, a museum, a farmer's market, hobby shop or shopping mall. If your mystery happens in a subdivision, make the neighborhood just a little unusual. You get the picture. Hint: Pick your favorite vacation spot.
1.a Historic Time Period. Setting includes the time period. Perhaps, the sleuth is an ordinary housewife or laborer but lives in the Great Depression, or between the World Wars. That ups the interest but also the research needed to make the story credible. Of course, if your sleuth is Queen Victoria's great-granddaughter (Rhys Bowen's Her Royal Spyness series) you have to investigate royal protocol as well.
2. Recurring characters. LOTS of them. A large family to go with the compound. Village residents who fit certain "types" - gossip, busybody, disorganized professor, teacher or minister, playboy, shopkeeper, etc. Neighbors with unusual hobbies or habits. Best friends, old folks who depend on the main character. Old folks who ARE the main characters. Fill up that setting and then you have fodder for a LOT of murders or suspects at least. Hint: Look around. You know these people.
3. Specific occupations or hobbies. The main character can't just be the sleuth, he/she/they must also create murals for cities, or build sculptures from recycled material, or have a lot of kids or take in rescue dogs or... It's convenient if they are law enforcement but a food writer or a pet groomer is probably more fun. Someone retired from academia or a profession that deals with people and their quirks will work as well. Use your imagination. OR use your passion.
4.TEACH! A book that teaches me something is a winner. This includes recipes, jargon specific to a craft or profession, the inner workings of a newspaper or the workroom of a library. Instructions on how to throw a pot or thread - is that the right word? - a loom, all add a touch of truth to your fiction.
5.Victim! It never hurts if the victim is either highly unpopular OR very rich with scads of possible heirs. This makes for LOTS of suspects. If the crime is NOT MURDER, (see my first paragraph), the victim can be sympathetic because that adds urgency to finding the lost object or missing person or blackmailer or the identity of the person in the mysterious photograph.
6. Humor. It can be hokey. Some series writers love using puns in their titles to set a light tone. Check out Donna Andrews' titles for an incredible list of bird-oriented puns. Earlier writers, like the venerable Wentworth and Marsh, added humor by emphasizing their characters' personality traits or habits. (Roderick Alleyn's sidekick, Inspector Fox, mangles the French language in almost every outing.) Joan Hess, in her Arly Hanks and Claire Malloy series, included characters with predictable traits and penchants for nosiness to up the laughs.
There you have it. I want to read what you concoct from these ingredients.
WHAT??!! I did not add "a mystery" to my ingredients? DUH! That goes without saying.
There should be confusion as to how and who and you should add clues, of course. But if you distract your reader with setting and recipes and wonky characters and a sweet little romance as a subplot, you might get away with something not too taxing.
What are you waiting for? Good luck! Get Writing!