The East Liberty art project that's a restaurant and a talk show bakes its last waffle tomorrow night.

Carnegie Mellon art professor Jon Rubin says it's simply time to shut down the venue he co-founded in 2008. "Creatively, the shop's kind of run its course. It's kind of less unexpected than it was," Rubin says.

The venue at 124 S. Highland Ave. will bow out with appropriate hoopla, however: Saturday night's "Cavalcade of Stars" is open to any of the 7,000 or so people who Rubin estimates have taken the Shop's stage.

That'll happen from 11 p.m. to 3 a.m., the shop's signature late-night hours. Or you can come earlier, between 10 a.m. and 2 p.m., for the popular brunch.

Waffle Shop began as one in a series of boundary-defying public-art projects Rubin undertook with students in the mid-'00s. Many were storefronts with conceptual premises (like a travel agency for imaginary journeys). The idea was to blur the line between commerce, art and social interaction, expanding the definitions of all three.

Waffle Shop is the one that stuck. The joint was a functioning diner, specializing in waffles and coffee. But its stage hosted talk shows that welcomed everyone from local performance artists to everyday people. (You can find video at www.waffleshop.org.)

It probably didn't hurt that Waffle Shop is in the heart of East Liberty's resurgent restaurant and nightlife area, and right around the corner from Shadow Lounge.

Still, says Rubin, Waffle Shop showed "how you could use food as a way of creating audience [and] how food created this great space for talking about politics" and other issues. "It created a site of comfort in public."

Anyone, after all, could wander in for waffles and end up watching an interview with a local artist, a discussion about unemployment or a cooking show, or participating in a Skype discussion with Iranian filmmakers.

Waffle Shop was originally open only on Friday and Saturday nights; the brunch came later. Rubin says that in addition to formal guests, in its four years Waffle Shop hosted between 20,000 and 30,000 people.

"I couldn't have foreseen that, that people would remain interested in participating in what we were doing," he says.

One performer active at Waffle Shop was Gab Bonesso. In February, the comic staged an "anti-talk show." She played a "childlike adult" living with her parents, whose program was co-hosted by her imaginary friends (as portrayed in the flesh by local actors). "It was everything I ever wanted to do onstage," says Bonesso.

She also hosted somewhat more conventional programs, including a show in which she interviewed children about being bullied.

Bonesso appreciated Waffle Shop as a venue.

"Because of Jon Rubin being so well versed in art, it lets you have zero boundaries," she says. "Literally anything can happen at the Waffle Shop."

"I don't think we have anything like it in Pittsburgh, and I'm sad to see it go," she adds.

Although Waffle Shop had the support of East Liberty Development Inc., building-owner Eve Picker and others, Rubin acknowledges that the project could be a financial strain. The space was rented. "It's a tough go running a restaurant, let alone running a restaurant and a talk show," he says.

To help defray the cost, Rubin says, Waffle Shop will be selling off its distinctive sign, tables and chairs — even the stage.

But Rubin says the main reason for closing the shop is that a sister venture in the same building, Conflict Kitchen, is taking more of his attention. Conflict Kitchen is a take-out window serving a rotating array of street food from countries the U.S. is at odds with, like Iran and Afghanistan. Plans to move Conflict Kitchen Downtown took precedence over continuing Waffle Shop, too.

However, Rubin says that a CMU-based art presence will remain onsite in the form of the billboard atop the Waffle Shop building, bearing provocative messages. So while the storefront will be silent come Sunday, for additional aesthetic stimulation, just look up.