“I’m feeling completely over the moon,” designer Daniella Kallmeyer said from inside her newly opened Madison Avenue boutique—a richly layered space that now serves as the brand’s Upper East Side flagship. Outside, French 75s and Aperol Spritzes flowed from a curbside cocktail cart, welcoming guests to a glamorous kickoff of what Kallmeyer dubbed the brand’s “uptown chapter,” an extension of its well-loved Orchard Street studio downtown.

Created in collaboration with designer Louis Rambert, the space is an elegant blend of French modernism and American Art Deco, punctuated with personal touches—like framed vintage recommendation letters for Kallmeyer’s grandmother, once a dressmaker herself.

By 7:30 p.m., the party migrated from boutique to banquet: Club Kallmeyer at the neighborhood stalwart Three Guys Diner. “I’ve been calling it Kallmeyer’s Bat Mitzvah—this is our thirteenth year in business!” the designer laughed.

Guests from fashion, film, and the art world turned out in full Kallmeyer—Chloe Fineman, Busy Philipps, Tommy Dorfman, Louisa Jacobson, Grace Gummer, Norma Kamali, Kate Young, Janicza Bravo, Laura Brown, and Sarah Hoover among them. “Everything I’ve ever put on from the brand looks good—and I feel like myself,” said Jacobson. Bravo agreed: “We’re so synced in the things that bring us joy. Dani inherently knows who her woman is.”

The evening’s many flourishes—a menu of diner classics on silver trays, bespoke Café Kallmeyer hats worn by staff (guests were already asking how to get one), and a cheeky two-martini menu (a vodka-based Uptown BODY, and a mezcal Downtown Yola)—were all helmed by an all-female dream team, including event producers Souvenir Shop and DJ Rae Sada, whose mix of pop and dance tracks spilled out onto the sidewalk.

As the festivities swelled, a surprise moment capped the night: a birthday cake for Rambert. “Louis was patient, chic, and his references were perfect!” Kallmeyer said before leading the crowd in a chorus of “Happy Birthday.”

The evening wound down with dancing under warm café lights, a scoop of banana Nutella or stracciatella, or a final cigarette in the early summer air. It was a party that proved what the best Kallmeyer pieces do—sharp yet soulful, sophisticated with a wink.