Oreo enthusiasts once again will have the opportunity to start their day with Mega Stuf Oreo O's, a limited edition breakfast cereal that Post is bringing back after three years. This dessert-themed cereal, which differs from the original Oreo O’s cereal with the inclusion of miniature marshmallows, is part of a limited-time reintroduction by Post Consumer Brands, along with the beloved Chips Ahoy! cereal. The original Oreo O’s were released in the ‘90s and discontinued in the early 2000s only to make a comeback in 2017. Mega Stuf Oreo O's were a limited release in 2019 and discontinued in 2020, but now they’re making a comeback and will be available at retailers nationwide for a limited time.