Cottage Food Acts in various states; California's Homemade Food Act awaiting gov's signature - please consider supporting
Thanks to the previous question by Niashi  about a similar law in Washington I learned about the the California Homemade Food Act, AB 1616, which has passed both Assembly and Senate and is awaiting the Governor's signature. I probably won't be in any position to take advantage of this myself, but others here might. Like other similar laws (Cottage Food Acts and the like) it would make it reasonably easy and affordable to become a licensed food producer at home, in part by making sure you take a short class on how to avoid making customers sick, by restricting the types of foods you can cook for sale in a home kitchen (seem like reasonable restrictions: various things like meat and dairy fillings are not allowed, stuff more likely to harbor bugs.) Considering it is currently not legal to bake and sell most anything this would be a big step up.
Something like 33 other states have similar laws, your state might well have one.
More information on this law, cottage food laws in general, a link to a pdf listing the laws in other states, and lots of resources for small food startups can be found at