Oh, you wouldn't put anthing in it that wouldn't pass muster by the FDA...but an ingredient that was a natural strong laxitive....
And destroy the baker’s business. Giving everyone at an event tummy distress but thinking no one will guess the baker is at fault is naive. The baker can expect health inspector scrutiny to end all scrutiny. In the meantime guests at the event are spreading the word that the baker “food poisoned” a number of people and watch his/her business crumble.