Unfrosted

Jerry Seinfeld’s iconic eponymous sitcom was famous for being “about nothing.” So is Unfrosted, although in a less intentional and less effective way.

The 70-year-old comedian’s belated feature film starring and directorial debut is a wildly uneven romp in which the noted cereal connoisseur explores the faux origins of the Pop-Tart.

Despite some scattered moments of inspired brilliance, the story careens between sketches with little regard for logic or coherence. Aggressively cartoonish and with a rather juvenile sensibility, the sugarcoated result is not for all tastes.

The playful period satire zeroes in on the absurdity of a Michigan town that became the epicenter for the burgeoning and highly competitive breakfast cereal industry in the early 1960s.

It’s set largely inside Kellogg’s, where product chief Bob (Seinfeld) and his executive boss (Jim Gaffigan) are locked in a ticking-clock race with crosstown rival Marjorie Post (Amy Schumer) to develop a viable breakfast pastry.

As part of his ragtag research team, Bob recruits a former colleague (Melissa McCarthy) now developing dried foods for NASA. However, he keeps getting sidetracked by complaints from a disgruntled Shakespearean actor (Hugh Grant) inside the Tony the Tiger costume.

Can they get the name and the marketing just right before Post does the same? And what about the conspiracies lurking behind the scenes?

You can see why Unfrosted has been a longtime passion project for Seinfeld, whose career of hilarious observations about the mundane details of everyday life seems appropriate for such a trivial obsession. “The magic of cereal is that you’re eating and drinking at the same time with one hand,” he reasons in a witty bit that could have been lifted directly from one of his stand-up routines.

The screenplay provides some intermittent big laughs, although it’s very hit-and-miss with its rapid-fire combination of sight gags and one-liners overflowing with industry and pop-culture lampoons. Among those caught in the crossfire are John F. Kennedy, Walker Cronkite, Jack LaLanne, and Chef Boyardee.

The film seems stretched at feature length, detoured by diversionary subplots involving a syndicate of vengeful milkmen, a sugar cartel, and an angry mob of striking mascots threatening an insurrection at company headquarters.

Bolstered by an amusing collection of quirky cameos, the film nevertheless is a concoction of wildly mismatched ingredients that makes more of a gluten-stuffed appetizer than a full meal.

Rated PG-13, 93 minutes.