What kind of a gift can you give your teacher out of respect, but that doesn’t get mistaken for romance?

A follow up from my older asklemmy post, saying goodbye to a teacher who helped me a lot through my stuff, was thinking maybe chocolate, but one of the dudes said that it’s not a very good idea, I was thinking maybe a perfume/cologne? What do you guys suggest? She is in probably in her early 20s if it helps, and I am in senior...