David Roffe, 70, swirled pink wisps of sugar floss onto sticks, thrusting pink clouds of cotton candy into the hands of young, stylish partygoers.

By day, Mr. Roffe, a stout, 5-foot-2-inch retiree, lives in the Rockaways. But last Thursday night, at the first Old Jewish Men Fall Ball, an intergenerational mixer held at Congregation Beth Elohim in the Park Slope neighborhood of Brooklyn, he was the talent.

Mr. Roffe is one of the faces of Old Jewish Men of New York, a lifestyle brand that embraces Jewish cultural stereotypes and means no disrespect. The event introduced Mr. Roffe, a brand ambassador, to fans who recognized him from skits — including a TikTok video in which he protested rising pastrami costs at Katz’s Deli.

A crowd of old and young enjoyed Mr. Roffe’s cotton candy, alongside bagels and lox, in the dim light of the temple’s art-deco ballroom — just as the party’s host, Noah Rinsky, had planned.

“It’s a bunch of old guys, a bunch of hipsters, and they’re both surprised to see each other there,” said Mr. Rinsky, who wore a beige suit and wire-framed spectacles. “So far, the collision has seemed fairly natural.”

Mr. Rinsky, a 33-year-old Park Slope resident, is the creator of @oldjewishmen, a popular Instagram account documenting individuals from its namesake demographic. It builds on the tradition of self-referential humor that has been embodied by personalities like Jackie Mason, Rodney Dangerfield, Larry David and Mr. Rinsky’s own father. With memes and videos, the account hopes to honor personalities Mr. Rinsky found around New York — and in his own family.

The eccentric antics of Mr. Rinsky’s father, Jeff, inspired the account, originally called @dadaroundthehouse, which started in 2015. After the elder Mr. Rinsky moved to Tel Aviv, his son looked closer to home for examples of quirky humor similar to his father’s.

“I needed more old Jewish men because my dad wasn’t around,” Mr. Rinsky said.

At the time, Mr. Rinsky lived below a Hasidic prayer center on Manhattan’s Lower East Side. Men would frequently knock on Mr. Rinsky’s door to request his help in meeting the 10-person quorum required for conducting Jewish prayer. He began taking candid photos of the men and including irreverent captions.

“I would spend a lot of time around there just taking pictures of these guys,” Mr. Rinsky said. “At that point, the account was a little bit more about the suffering of aging.”

Mr. Rinsky is aware that the brand’s humor often hinges on tropes — relating to both Jews and older people — that can be reductive.

“My dad isn’t crazy about some of the stereotypes. I think that he thinks it’s funny, but wishes at times there was a deeper more spiritual approach,” he said.

“I think O.J.M. is funny,” he added. “I don’t think all Jewish men are sitting around eating pastrami and sitting in saunas all day. But obviously, it’s a multifaceted group.”

But Mr. Rinsky soon found there was a market for niche content about New York’s irreverent Jewish elders. He brought in Bryan Seversky, a creative director from Los Angeles. Building on the popularity of the Instagram account, the two men started a clothing line, a podcast and a TikTok account, which features scripted skits and pearls of advice from resident O.J.M.s like Mr. Roffe. A book, “The Old Jewish Men’s Guide to Eating, Sleeping, and Futzing Around,” will be published by Workman Publishing in 2023.

Now, O.J.M. has started hosting live, intergenerational mixers modeled after old-school socials that connect the brand’s fan base with real elders behind its aesthetic inspirations. (O.J.M.’s style, Mr. Rinsky and Mr. Seversky said, is “geri-core” — or “geriatric-core.”)

“It’s pure fun,” Mr. Rinsky said. “The food isn’t kosher, and not everyone’s Jewish, but they share the same desire to meet like-minded people who would be attracted to this same out-of-era event.”

The events at Congregation Beth Elohim grew out of a chance encounter with the synagogue’s assistant rabbi, Matt Green, 32. He first met Mr. Rinsky at a coffee shop near the temple in Park Slope when he spotted Mr. Rinsky in an O.J.M.-branded ball cap.

“I asked him where he got it, and it turned out he was the genius behind the Instagram account,” Rabbi Green said. “I introduced myself as a rabbi, and we got to talking.”

Rabbi Green was an instant fan. He felt O.J.M.’s identity was both cool and confidently Jewish, a combination he strives toward in his own cultural programming. In addition to his rabbinical duties, much of Rabbi Green’s work at Congregation Beth Elohim has involved getting creative about how to make Jewish life relevant to a younger, increasingly secular generation.

“Many in Jewish establishments are concerned about younger Jews not believing in things or caring about things that older generations cared about,” he said.

In Mr. Rinsky and Mr. Seversky’s project, Rabbi Green saw a flipped script. Beneath the facade of its often sarcastic humor, O.J.M. — as Rabbi Green sees it — expresses a real desire to connect with and archive aspects of American Jewish culture that are disappearing with time and assimilation.

“He’s preserving these voices and this aesthetic and this attitude toward life that won’t be here forever,” Rabbi Green said.

He added, “He’s also, I think, inviting us into it to figure out what of this do we want to take on beyond our generation.”

When Mr. Rinsky mentioned he was interested in offering in-person social events for O.J.M.’s fans and followers, Rabbi Green suggested Congregation Beth Elohim as the venue.

“I thought it was a perfect shidduch, which is to say a perfect match between what he was doing and the fact that I have an intergenerational community, but also a community that includes many people in their 20s and 30s,” Rabbi Green said.

In July, Rabbi Green and Mr. Rinsky hosted O.J.M.’s inaugural event at the synagogue, a “Speed-Schmoozing” night, whose M.C. was Willie Zabar, a comedian and a fourth-generation member of the Zabar family. The event was successful enough that Rabbi Green and Mr. Rinsky decided to host the O.J.M. Fall Ball.

Attendees enjoyed the crooning musical comedy of Dani Luv, who had performed at Sammy’s Roumanian Steakhouse on the Lower East Side, which is now closed. There was food from Greenberg’s Bagels in Bedford-Stuyvesant and Edith’s in Williamsburg, two millennial-run Jewish sandwich shops. O.J.M. apparel — parody Mets merchandise emblazoned instead with the word “MEATS” — was available for purchase.

“I’m surprised that it’s almost exactly what it was billed as,” said Lucy Dolan-Zalaznick, 25, who works on the socials and visuals team at Vogue.

For Mr. Roffe (who hit the dance floor after his shift at the cotton candy machine), the fall ball was an opportunity to get out during a time of life when social opportunities have grown more sparse. But through experiences with O.J.M., Mr. Roffe has found new friends and new Hora partners.

“You have to live life like a kid,” he said. “You only come around once!”

Without a brick-and-mortar store to call home base, O.J.M. plans to continue hosting pop-ups and socials at Congregation Beth Elohim and elsewhere (the brand’s next event, a comedy brunch show called Deli Laughs, presented at Stand Up NY, will take place on Dec. 11.) Mr. Rinsky also suggested there could be another ball this spring at the synagogue.

And the older guests? Many sat in folding chairs on the right side of the ballroom, nursing drinks and wondering aloud about the youthful crowd.

“Why aren’t they going to Justin Bieber concerts?” said Aliza Hyman, 58, from Brooklyn, who had stopped by for some cookies and scotch at the invitation of her friend Aaron Cohen, a 70-year-old paid actor who appears in O.J.M.’s skits.

“When I was that age, we would never come to a mixer that wasn’t hip,” Ms. Hyman said. She turned to her friend. “But maybe this is hip,” she said. “Maybe this is what’s happening.”