I haven't been into cozies for a while, but I just read one recently that I enjoyed, "Dead in Dublin" by Catie Murphy (who is really C.E. Murphy, author of the Walker Papers series, among others). The heroine wasn't an annoying TSTL busybody, which is so often the case in cozies. I'm actually going to buy the next book when it's released.
I think that my biggest pet peeve about YA books is that they aren't often labeled upfront as such, so if I see a new book out by a favorite author, I think, "hot damn", then I read the synopsis and see that it some series about a wayward wizards academy, or a group of young tech whizzes, or some such thing, and my anticipatory hopes are dashed. I think that the introduction of the character of Wesley Crusher into Star Trek scarred me for life.
In recent years, I've been mainly a sci-fi/urban fantasy/mystery reader who somehow never hopped aboard the Harry Potter train, so any story line that seems to be a knockoff of it holds no interest - and so many YA SF/F books seem to be variations on the mythic academy theme. Or, it's a coming-of-age story and I've already got a pre-teen and a teen in my life - I can experience the drama in real-time, lol.