Bill Post, who helped create the on-the-go breakfast as an inventor of Pop-Tarts, leading the Michigan baking team that developed an unpretentious, toaster-friendly pastry with a fruity filling and ineffable space-age sweetness, died Feb. 10. He was 96.

His family announced the death in an obituary through MKD Funeral Homes in Grand Rapids, Mich., but did not say where or how he died. Post had been living at a senior-living community in the city, not far from the baking plant where he fine-tuned Pop-Tarts in 1963.

Tastes have changed since then, although the foil-wrapped snack has largely remained the same, enduring as a sugary staple of family kitchens and school cafeterias while encroaching on the turf of traditional dishes like oatmeal, eggs and bacon. The pastries may lag far behind in nutritional value, with upward of 30 grams of sugar in each frosted pack, but they sell by the billions each year, bringing in about $1 billion in annual sales for Kellanova, a successor to Kellogg’s.

Eaten toasted or raw, Pop-Tarts have lodged themselves in the cultural and culinary firmament, joining a processed-foods pantheon that includes all-American brands like Cracker Jack, Twinkies and Spam.

“What Pop-Tarts did was use an appliance that had only been used for sliced bread,” Barb Stuckey, chief innovation officer for the food development company Mattson, said in a 2015 interview with Adweek. “Breakfast pastry had been around forever, but making it convenient was truly unique.”

The snacks have been lampooned by “Family Guy” and “Saturday Night Live,” which poked fun at the brand through an ad for Tasty Toaster Tarts, “the treat kids crave.” Comedian Jerry Seinfeld, who said he prefers his brown sugar cinnamon Pop-Tarts with a glass of milk, is directing a Netflix comedy film inspired by the food, “Unfrosted: The Pop-Tart Story,” slated for release in May.

Last year, the pastry even became a surreal emblem of college football through the Pop-Tarts Bowl, which culminated with the “death” of the game’s mascot, an anthropomorphic Pop-Tart named Strawberry. After the mascot descended into a giant toaster, an oversized Pop-Tart was released through a slot at the bottom and devoured by the winning team. A single googly eye, the last vestige of Strawberry, was all that remained.

“We didn’t realize that this thing was going to go as well as it did,” Post told CNBC a few days before the game, reflecting on Pop-Tart’s origins. “It went beyond any expectations we had.”

A former truck washer and cookie baker who climbed the corporate ranks, Post maintained an aw-shucks modesty around his role in the pop-start of Pop-Tarts, which began with a 1963 call from Kellogg’s. The cereal giant was competing with archrival Post, which would soon launch a breakfast pastry called Country Squares, and needed help developing a similar product that it didn’t quite know how to make.

Turning to Hekman Biscuit Co., which soon became part of the Keebler Co., the business found an ally in Post, Hekman’s plant manager, despite the fact that he happened to share the name of their corporate rival.

In a promotional video for Kellanova, Post recalled the day that four Kellogg’s executives visited the baking plant with a prototype: a pielike pastry, shaped like a slice of bread, with “fork marks around the edge - two pieces of dough with some filling in it.”

“They said, ‘We have this idea. We’d like to put that in a toaster.’”

As he told it, his boss scoffed at the idea. Post embraced it, steering the project through technical challenges in a frenetic four-month scramble to bring the pastry to market.

“At the time, I thought it was a great idea,” he said in a 2003 interview with Northern Express, a Michigan newspaper. “But as we became more involved, it sort of had to work, because man oh man, I had my neck out so far on the equipment and getting unauthorized shipments of equipment from other facilities without permission and without accounting records, and just plowing through and getting this thing done. In retrospect, we expended hundreds of thousands of dollars, so this thing had to go.”

He realized he had a hit product, he said, when his children kept asking to try more samples of his “fruit scones,” as the pastries were originally called.

The product was given a snappier name, Pop-Tarts, in a nod to the pop art movement, according to a company history. And while Andy Warhol may have never painted a foil-wrapped Pop-Tart, the snacks seemed to fly off shelves faster than cans of Campbell’s Soup: According to Post, the initial 1963 test release in Cleveland was boosted from 10,000 to 45,000 cases of the four original flavors (strawberry, blueberry, apple currant, brown sugar cinnamon) to keep up with demand.

Pop-Tarts were officially rolled out across Cleveland the next year and sold nationwide beginning in 1965. Originally manufactured with rounded corners, the pastries evolved into sleek rectangles, punched with small holes to prevent steam-induced sogginess when they were toasted. Their signature frosting was introduced in 1967. Post told the Associated Press that he came up with the idea himself, after running Pop-Tarts through a cookie-icing machine; to his delight, the frosting didn’t melt, and the new glaze was embraced by Kellogg’s executive William E. LaMothe, who instructed him to add frosting to each variety.

“We just doubled the market with that one decision made in one day,” he recalled.

Post rose to become a senior vice president at Keebler and spent two decades as a consultant for Kellogg’s. He said he continued to eat three or four Pop-Tarts a week into his 90s and always had a pack on hand in his car, which he emblazoned with a “POPTART” license plate. His favorite: frosted strawberry, untoasted.

“I eat them cold,” he told Northern Express, “just the way they are.”

One of seven children of Dutch immigrant parents, William Post was born June 27, 1927, and grew up in Grand Rapids. His father was self-employed, according to the New York Times, and drove a truck around town, taking away the ash that people removed from the bottom of their coal furnaces.

The family was “poor as church mice,” Post recalled, so at age 16 he took a part-time job washing trucks for Hekman. After graduating from Grand Rapids Christian High School, he served in the Army Air Forces in occupied Japan and returned home to resume his work at the baking company.

Post studied for two years at Calvin College (now a university) in Grand Rapids before deciding that he was happier at the bakery than he was in the classroom. At 21, he left to become a full-time personnel manager for Hekman. He moved to Elmhurst, Ill., in 1967 to work in Keebler’s corporate office and briefly retired at age 56, moving to a lakeside home in Glen Arbor, Mich., before Kellogg’s coaxed him back to work as a consultant.

His wife of 72 years, Florence (Schut) Post, died in 2020. Survivors include two children, Dan Post and Rachel DeYoung; four grandchildren; and 10 great-grandchildren.

Post served on the board of schools, churches and the YMCA, according to his family, and was a member of the evangelical Christian group Gideons International. He often spoke to schoolchildren about his business career, “bringing some of his unending supply of Pop Tarts with him,” the family said in his obituary.

Other times he decamped to a workshop in his basement, where he carved wooden Santa statues under a sign reading, “Nooitgedacht.” It was Dutch, Post explained to the Times, for “Never woulda thought.”