More than a thousand people gathered for a picnic on Saturday around tables draped with white tablecloths and spread over the lawn of the Legion of Honor art museum in San Francisco.

There was just one rule: “No cake, no entry.”

Attendees — including pastry chefs, home bakers and people with store-bought cakes — walked, drove and flew to bring elaborate cake creations to Cake Picnic, a touring festival where you can have your cake and eat it, too.

“It was harder to get than a Taylor Swift concert ticket,” said Elisa Sunga, Cake Picnic’s organizer, noting that the $15 tickets sold out in less than a minute.

This Cake Picnic turned out to be the biggest since it started nearly a year ago. Ms. Sunga described the intense interest in the festival as both “exciting” and “terrifying.”

A spectacular variety of cakes adorned the tables, including: a light lemon cake with passion fruit filling, a tower made out of smaller spongecakes, Jell-O cake, pink champagne cake, a kid-baked dinosaur pyramid cake, and plenty of desserts with flowery ornaments.

In the first hour, picnickers placed their cakes on stands and crammed them onto the tables. Then, after the arranging was complete, came that fleeting and glorious moment: The crowd gawked and took photos of the 1,387 cakes, both sweet and savory, in their pristine, unsliced form.

After the photos were taken, the ensuing buffet was an act of controlled chaos.

Smaller groups went up for cakewalks. Each person was given a pastry box and instructed to collect slices at will. Once everyone had a turn, the tables were opened for ravenous seconds, thirds and fourths, until no crumbs were left behind.

In April 2024, Ms. Sunga, a 34-year-old home baker, hoped to gather about a dozen people in Potrero del Sol Park in San Francisco to sit in a circle and eat cakes that they had baked and brought.

“It started primarily because I wanted to eat a lot of cake,” Ms. Sunga said. “I love cake.”

She posted the gathering on the invitation app Partiful, and it took off. Hundreds of people responded.

After the first event in April 2024, she took the cake show on the road, first to Los Angeles, then to New York and then back to San Francisco in November — “places with cake communities,” she said. At the last picnic, 613 cakes were on display.

“It’s not my full-time job, but I would love to travel full time for cake,” said Ms. Sunga, who works at Google. “It’s taken on a life of its own.”

Ms. Sunga, who brought two red velvet cakes of her own, said chefs from well-known bakeries, such as Tartine and SusieCakes, attended.

The Legion of Honor, the picnic venue, opened a special exhibit last week, “Wayne Thiebaud: Art Comes from Art,” celebrating Mr. Thiebaud, who died in 2021 and is most famous for his decadent paintings of cakes and confections.

The Cake Picnic aimed to turn his dessert still lifes into a “living tribute,” according to the museum’s website.

Joyce Lim, 32, who lives in San Francisco, called herself a Cake Picnic “groupie.” She said that she has baked for every Cake Picnic so far and will attend future picnics set for London and New York. (A two-day April picnic in Carlsbad, Calif., is sold out.)

Ms. Lim, an architect, said she has embraced cake baking for the picnics after at first being intimidated by it. On Saturday, she brought a scallion-pancake focaccia cake with chili-crisp cream cheese frosting and crème fraîche.

“I enjoy procrasti-baking, basically baking instead of handling my other life responsibilities,” Ms. Lim said.

She said she has been impressed by the creativity and diversity of cakes that people bring. Her cake might just top her previous elaborate entries: a kabocha cake layered with ginger-poached pears and miso-caramel cream cheese frosting, and a smörgåstårta, a Swedish cake with rye layers, hard-boiled eggs and caper filling.

Brenna Fallon, one of dozens of volunteers at the picnic, said that the brief period after the cakes are laid out and before the buffet begins is an “‘Alice in Wonderland’ moment.”

“Everybody is just gleefully going through the aisles,” said Ms. Fallon, 34, who is from Walnut Creek, Calif. “People are plotting — which cakes do they want to make a beeline for when they get in?”

Ms. Fallon, an amateur baker who brought an Earl Grey chocolate cake with a salty buttercream, said that a feeling of celebration was in the air.

“It’s a slice of life,” she said. “It feels like a big picnic with a bunch of friends you just don’t know yet.”