What did William Keith kellogg accidently invent?

William Keith Kellogg accidentally invented cornflakes in the late 19th century while experimenting with a wheat dough intended for granola. After leaving the dough out to sit, it became stale, prompting him to roll it out and bake it, resulting in crispy flakes. This serendipitous creation led to the development of the Kellogg Company and revolutionized breakfast cereals.