Unfrosted, a movie about the race to create a game-changing breakfast pastry, such as, say, the Pop-Tart, debuts on Netflix May 3. Jerry Seinfeld directs, his first time directing a film.

“Who can make the Pop-Tart is the same as who can land on the moon first.” Seinfeld, who co–wrote the film with his “Bee Movie” and “Seinfeld” collaborators Spike Feresten, Barry ...