In 1963, Bill Post helped create the first toaster pastry, and what would eventually become Pop-Tarts. Kellogg asked Bill to help bring an idea to life, which he did. Pop-Tarts were first test-marketed in 1963, made largely available in 1964 and launched nationally in 1965. When they debuted in September 1963, Pop-Tarts came in four flavors: Strawberry, Blueberry, Brown Sugar Cinnamon and Apple Currant.

In 1967, Bill had the idea to frost the treats, which was a hit. The Kellanova team, previously Kellogg, was thrilled to welcome Bill back to the plant where the magic started. Watch the video to hear Bill share his experiences in co-creating this iconic brand.

Now, 60 years later, Pop-Tarts continues to be a Crazy Good choice for hungry consumers. CNBC goes in-depth on just how popular the brand continues to be after six decades.