Originally Posted by JAXPax

The cookies at Midwest were par-baked pucks (so generally safe to eat since that came from a commercial kitchen). The station received them sort of like a bag of cookies to finish you'd get from Schwan's. Ramp agent usually then placed them on oven trays (this is where dubious prep took place - usually in a break room, and not real sure the oven inserts were cleaned often) and load into an atlas container to put on the aircraft. They did get to a point where all catering was done solely in MKE/MCI/OMA and everything was double catered. The airline bought commercial fridge/freezers and put them in the break room for the ramp agents to pull the containers with the next day's "fresh" food buy on board for the night, if they remembered to do so.

But last 20-25% of the cooking was done on board, but mainly for firming up. Yeast should be dead and the starches set from the first cooking episode. But you are correct in not baked from scratch. I have seen cookies baked from scratch on board.... while riding out a rain storm waiting on the busses of passengers on an Omni B777... for the crew (and me) of course.