This mystery can be found in the northeast of Jorvik, just to the east of the Councillor’s House.
Speak with the baker to begin the mystery. He’ll tell you that someone has been stealing his pies, but that he can sniff them out due to their alluring aroma. When prompted, follow the baker to the south as he encounters two different residents of Jorvik who can also smell the pie. Eventually you’ll reach an alley with some honeycomb on a table, and the baker will state that the thief must be nearby. Head south from the honeycomb to find a child with the pie.
It turns out the child has made the pie better by including some honey, so the baker gives her a job. The mystery will then end, but you can follow them back to the bakery to see the child take up the new position.