Poinbank Exchange|A crowd of strangers brought 613 cakes and then set out to eat them

SAN FRANCISCO – They came from San Francisco,Poinbank Exchange they came from Oakland, they came from New York and Seattle. And each and every one of them bought a cake.

A total of 613 cakes, to be exact.

At Cake Picnic, there was but one cardinal rule: "No cake, no entry."

Like a fever dream of cake goodness, hundreds of bakers converged at San Francisco's Legion of Honor museum on Saturday. The scene was like something out of a children's book: Dozens of long tables adorned with cake upon cake upon delicious, majestic, enticing cake.

Layer cakes, bundt cakes, square cakes, four-foot-long cakes, birthday cakes, tiered cakes, tortes, wedding cakes, slumping cakes and cupcakes – "It's a cake potluck. Or a cake heaven, cake nirvana, cake buffet. Call it whatever you want to call it – I call it a cake picnic," said organizer Elisa Sunga.

The Saturday event drew hundreds of people who collectively brought 613 cakes. On a sunny, crisp and glorious fall day in the far northwest corner of San Francisco, Sunga was surrounded by proud bakers, happy onlookers and many, many cakes.

"There is only one requirement: That you bring a whole cake. You can buy it at the store or make it yourself. But you have to bring a cake," said Sunga.

Maggie Rummel came because it sounded like heaven.

"I just wanted to eat a lot of different cakes, sit on the lawn and just sugar out." She baked an orange olive oil cake with marmalade filling and mascarpone whipped cream.

Sasha Sommer saw a notice about Sunga's first cake picnic in April but wasn't able to make it, so she bought tickets to Saturday's event back in July so she wouldn't miss it.

"I love cake," said the 32-year-old. Her parents happened to be in town and given the one-person-one-cake rule, they spent Friday baking.

"It was madness at our house, making three cakes," she said. "My mom made apple cake, my dad made a lemon olive oil cake and I made a 10-layer burnt honey Russian cake."

Abou Ibrahim-Biangoro also missed the first cake picnic but was determined not to miss the second.

She made her frosting on Thursday and did the baking on Friday. "It's a brown butter and oat cake with fig leaf syrup and buttercream frosting," she said. The cake was then artistically decorated with roses.

Ibrahim-Biangoro, 30, is a Ph.D. student. Beaming at the tables full of cakes, she grinned. "This is my stress release," she said.

How Cake Picnic got started

It began as a simple gathering of friends in San Francisco in April when Sunga decided if the cookie exchange she'd attended at Christmastime was fun, then a cake extravaganza would be the best of all possible worlds.

"I just love cake so much. I thought maybe 15 of us would come," she said. "We could bring friends, meet new friends and eat a lot of cake."

So she posted an invitation for a "cake picnic" on social media. Before she could close the invite list, 360 people had RSVP'd. On the day of the event, 183 cakes and their minders came.

"Everyone stood in a circle, introduced themselves and said what cake they'd brought," she said. Then everyone ate cake.

The next month she did another, in Los Angeles. That drew 253 cakes and their minders. Two weeks ago she held one in New York, which drew more than 300 cakes.

The return to San Francisco, where Sunga lives, surpassed them all. "We received over 1,000 RSVP's and there are 300 on the waitlist," she said.

San Francisco's second Cake Picnic

Sunga had already organized three Cake Picnics when the Legion of Honor museum reached out. "They said, 'We're celebrating our 100th birthday, can you come bring cakes?'"

The gathering was held in front of the museum while the museum celebrated with speeches and a high school marching band in its French neoclassical courtyard just steps away.

"They supplied cake boxes for everyone. I've never attended a 100th birthday party, it was fun to create an iconic event with them," Sunga said.

It was also a nice reminder that while much of the country might think of San Francisco as a place for "tech and weirdness," as Sunga put it, "we're actually full of creative people who are just excited to do fun, community-oriented things like this."

What happens at Cake Picnic

First, people register. Then they get a cake, which, by the look of the gathering, most had baked themselves.

Then, on the day of the day of the event, the choreography of cake sharing begins.

Outside, hundreds of women and a smaller number of men streamed to the lawn where dozens of long tables were set up to receive their cakes. There was an entrance, where volunteers were assured that every attendee did indeed have a cake.

Each participant received a color-coded name tag, placed their cake on a table and then had about an hour to wander from table to table, admiring the myriad examples of the bakers' art.

After a brief welcome, Sunga began calling up groups based on the color of their name tag and each group had five minutes to get as many slices of cake as they chose before the next group came over.

"The first group has the honor of cutting up all those cakes," said Sunga. "People were asked to bring a cake cutter and apparently on Friday there was a shortage of cake knives in San Francisco."

Sunga's own cake was a 4-foot extravaganza. "There are three cakes in there. There is a dark chocolate hojicha cookies and cream. A banana peanut butter chocolate cake and the last flavor in that long cake is the strawberry almond Funfetti cake."

No cake went to waste, she said. After attendees ate their fill, they got to take pieces home, with many saying they planned to hold their own cake-tasting parties.

By the end of the event "it was just crumbs and boards," she said.

With the air perfumed with the scent of sugar, spices, butter and cream, Sunga said she planned to do more Cake Picnics again next year including an event in London in July. "I just love cake so much."

(This story was updated with new information.)