What a nice story! I liked the length, the protagonist, and the fact that it eschewed some of the simplistic tropes that books for kids often suffer from. For instance, the book didn't pretend that once the Bad Guys are dealt with, all problems disappear. Instead they were acknowledged without bogging the story down.
The part in the middle was too drawn out though, and could be improved by tighter editing, I think.
In the first third I kept thinking the dough magic could be explored more - and in the last third, it was. I also dislike how the blurb mentions the "sourdough familiar" that comes up maybe three times in the book, when there is a different familiar that was in every scene and actually had a personality. I guess "gingerbread man" didn't sound as good to the marketing team.
By the way, if you like the idea of a world where random people have random, individual magical talents - maybe take a look at Wildbow's Worm. It's not the same genre: it's for mature audiences and it's very long. But it builds an amazing world around this premise.