Kellogg Co., the 116-year-old maker of Frosted Flakes, Rice Krispies, Pringles and Eggo, will split into three companies focused on cereals, snacks and plant-based foods. Kellogg’s, which also owns plant-based food brand MorningStar Farms, said Tuesday that the spinoff of the yet-to-be-named cereal and plant-based foods companies should be completed by the end of next year. Kellogg’s had net sales of $14.2 billion in 2021, with $11.4 billion generated by its snack division, which makes Cheez-Its, Pringles and Pop-Tarts, among other brands. Cereal accounted for another $2.4 billion in sales last year while plant-based sales totaled around $340 million. In...