The Case of the Poisonous Cakes

From the introduction:

Hansel and Gretel were young brother and sister, who liked to play in the woods. One day, they wandered too far, and found a house made entirely of beehives. It was sweet and dripping with honey. And inside was the smell of wonderful baking. They entered the house and were greeted by a charming, plump lady who invited them in for supper. They grabbed at the sweet cakes, but she told them they would have to eat their greens before they got any pudding, even if there was so much just lying around in that honeycomb house.