Credit and Source: Forrager @ https://www.forrager.com/laws
Illinois has two different laws in place that allow the sale of homemade food. This page covers the older law, which is for “cottage food operations”. The newer law is for “home kitchen operations,” which you should use if you want to sell baked goods outside of farmers markets. Aside from being able to sell outside of farmers markets, the newer law is more restrictive than this older one.
This law only lets you sell cottage foods at a farmers market*, and you can sell up to $36,000 or products per year. The startup cost for your cottage food operation could be as low as $100, but it could be higher if your local health department has decided to charge fees for registration and an inspection. This law is also very specific about what types of food are allowed.
* Products with a locally-grown main ingredient can also be sold on the farm that grew the main ingredient, or delivered directly to the consumer.
In addition to farmers markets, products that have a locally-grown main ingredient (such as strawberry jam with locally grown strawberries) can be sold on the farm that grew the main ingredient, or delivered directly to the consumer.