Hullo!! Does anyone here have any experience selling homemade treats?

I work in a tiny all-vegan grocery, and I think one of my "veganized" recipes for some dessert bars would sell nicely in the shop if I wrapped them individually. I'm not trying to start a separate business or launch a product line, though. Is anyone familiar with any permits our shop would have to carry (or if I'd have to apply personally) in order to sell homemade packaged treats? I've also heard that I can offer them for a suggested donation, and any money received would be a "gift" and I wouldn't have to apply for anything / report the "sales". That sounds a bit shady to me, though, and is obviously not a viable long-term option.  ::)

Thanks guys!