In Michigan, the Food Law requires that almost anyone processing, storing, or selling food or drink to the public needs a license. There are some exemptions that allow a business to make or sell food with a license, but all other federal, state, and local laws and zoning ordinances must be followed. Most license-exempt businesses are subject to inspection by MDARD or by local health departments to ensure food safety and compliance.
The type of license (and who manages the license) depends on where you are selling it, what type of food you are selling, and whether that product is sold for consumption as part of food service or retail.