The Unbreakable Kimmy Schmidt costars will appear in Sonic’s newest commercial campaign, shared exclusively with PEOPLE, as part of the restaurant chain’s 16-year-old tradition of embracing improv comedy.
“I love their food, and I’ve been a fan of their commercials for years,” Kemper, 37, tells PEOPLE of why she wanted to get involved. “I love improv, and Peter and T.J. are huge comedians. I feel like it’s such an honor to follow in their footsteps. So all of these reasons combined, it was a no-brainer.”
Though Kemper couldn’t remember what lines specifically were improvised and what weren’t while on set in Pasadena, California with Krakowski, 49, she says it was encouraged.
“Everyone kept the spirit loose and light hearted, and Jane and I could give a lot of input ahead of time,” she says. “It felt very collaborative which is always nice when you are in a campaign like that because you want it to feel sincere. We were encouraged to riff and put our own spin on things.”
Getting to share this opportunity with Krakowski was special for Kemper, and she says they both got to channel a bit of their Unbreakable Kimmy Schmidt characters for the commercials.
“We have developed such a nice rapport over the years and our characters on the show are so funny together,” she says. “This campaign was a little bit different because it drew on aspects of our characters on Kimmy but it also was heightened versions of Jane and Ellie in real life. I think it was a middle ground.”
She adds: “It just feels really effortless with Jane all of the time and natural. Honestly, like I was hanging out at a drive-in with my friend.”
Kemper says that she and Krakowski “were under the impression that there going to be endless milkshakes everywhere” on set, but since they filmed at an actual Sonic location, they had to shut everything down.
“There weren’t as many as we thought because we thought there was going to be bottomless,” she says. “The kitchen actually was not open, but they surprised us and they made everyone shakes. I think one person came out with a shake and immediately all the crew and everyone was like, ‘Where’d you get that shake?’ Then suddenly there were many, many shakes going around because you can’t film a Sonic commercial and not have a milkshake.”
She continues: “It made me hungry just passing the scripts back and forth, I would salivate every time!”
Kemper, who is “passionate about ice cream,” says that her love of the dessert hasn’t passed on to her and husband Michael Koman’s nineteen-month-old son, James Miller.
“I am a little bit in shock because for his first birthday I was like, ‘I’m going to give James ice cream!'” she says. “And he didn’t like it! I am passionate about ice cream, I love it. This is probably not a bad thing that he doesn’t love ice cream just yet but don’t worry, I’m going to keep trying until something sticks.”
The new commercials feature upcoming Sonic products and promotions including the launch of the Signature Slinger, a new burger that’s less than 340 calories and made with a 100% pure beef patty that’s blended with mushrooms and seasoning. They also introduce Sonic Nights in which ice cream, slushes, shakes and floats will be half price after 8 p.m starting March 5.
Next, Kemper and Krakowski will return to Unbreakable Kimmy Schmidt for it’s fourth season premiering on May 30.
“I just finished filming the second episode of Kimmy for the season, and I don’t know much beyond the first two episodes because we haven’t read the rest of the season yet,” Kemper says. “Everyone is back. I thought last season was the craziest, weirdest, funniest one yet and so far I feel like it’s getting heightened even more.”
This season, Kemper is most excited about fans getting to see her character’s new wardrobe.
“Kimmy is a working girl,” she says. “What I’ve enjoyed the most about her so far this season is her new wardrobe — which is like Kimmy’s version of businesswoman, and it’s fantastic. She’s evolving. It feels frivolous but also really important because she’s maturing as a woman and her wardrobe is reflecting that.”