Which city claims to be the world largest producer of breakfast cereal?

The city that claims to be the world's largest producer of breakfast cereal is Battle Creek, Michigan, USA.

This claim stems from the fact that Battle Creek is home to the Kellogg Company, one of the world's largest cereal manufacturers. While it's not officially confirmed as the "largest producer", Battle Creek is undoubtedly a major center for cereal production and has a rich history associated with the industry.