I think it would be really weird for a man beyond his 20s to present female flight crew with personal gifts out of the blue. Too easy to create a creepy subtext even if the gesture is meant as innocent. It also sets up a vague expectation of reciprocation, in the form of personal contact or good / better service, which I think could make FAs uncomfortable. I think treating them like human beings and making eye contact and saying please and thank you, not being an imperious finger-snapping DYKWIA, is more appropriate than thrusting chocolates at them. And I would not be surprised if some airlines' security protocols forbade staff from eating gifts from strangers anyway.