Devil's Food — Kerry Greenwood

If there's one thing Corinna Chapman, baker extraordinaire and proprietor of the Earthly Delights Bakery, can't abide, it's people not eating well--particularly when there are delights like her just-baked, freshly buttered sourdough bread to enjoy. So when a strange cult which denies the flesh and eats only famine bread turns up and a malnourished corpse is found in a park, Corinna is very disturbed indeed.

But she doesn't only have that to contend with. Her hippie mother, Starshine, has turned up out of the blue, hysterical that Sunlight, Corinna's father, has absconded to Melbourne with all their money and a desire for a new young lover. Meanwhile, someone is also poisoning people with weight loss herbal teas. And odd things are happening at the nearby Cafe Vlad Tepes, which attracts a very strange clientele.
The third in the Corinna Chapman series.