I don't think it's that unusual, Emaa, if you get on well. I've have turned up for supervisions bearing cake before now. And cheese! (one of my supes is French!) It would be weird if you were making heart-shaped cookies and leaving them by the door every day, but if it's just a random thing I'm sure it's fine. If you don't have a friendly/chatty type of relationship, then I wouldn't do it - but I've been to their houses for dinner, they have often given me books with handwritten messages, etc. As long as you're not showering them with gifts or obviously making them feel uncomfortable, I wouldn't worry.