Jenna Fischer on 'Fun' Time Reuniting with “The Office” Cast for New AT&T Ad: 'It Was Over Too Fast' (Exclusive)

Fischer tells PEOPLE about the "thrilling" experience of reuniting with her costars for a new AT&T Business ad — and how the cast's Office Peeps text thread is still "going strong"

When The Office cast gets back together, it's like no time has passed. That's exactly what happened when some of the gang reunited for an all-new AT&T Business ad, according to series alum Jenna Fischer.

"It was so much fun and totally seamless," Fischer, who played Pam Beesly across the show's nine seasons from 2005 to 2013, tells PEOPLE exclusively. "We locked into our chemistry together immediately. It was so thrilling. It was over too fast. I wish it had gone longer."

"I think [Ed Helms' character] Andy had a line where he says, 'If only you knew you were in the good old days when you were in them.' I'm paraphrasing, but it's that idea," she continues. "And, listen, we knew we had a great thing when we were filming The Office. But this was that chance to go back and re-experience that magic for just a moment, and that is such a gift to be able to do that."

Related: 'The Office' Cast: Where Are They Now?

The Blades of Glory actress shared, "It was like getting to play with your winning football team one more time. It was so great."

Fischer, 50, got to reunite with former costars Rainn Wilson, Craig Robinson, Creed Bratton, Kate Flannery and Brian Baumgartner to help show how AT&T's reliable Next Level Network can help small businesses succeed.  In the ad, the Dream with Rainn company demonstrates the creation of an innovative new sleep therapy device, a.k.a. the Sleep with Rain pillow, which boasts a speaker inside it.

Recalling one of her favorite moments from shooting the ad, Fischer says she enjoyed getting to share the screen with Robinson, which is something they rarely got to do on the NBC comedy.

"When I was on The Office, Pam and Daryl, the characters of Pam and Daryl, we were the voice of reason a lot of the time. And we didn't get teamed up very much for storylines because they would always have to team us up with an unreasonable person so that we could be the reasonable person," she explains of the pair's two characters. "Every once in a while, Pam and Daryl did get to team up, and it was so great."

The pair appeared to be a dynamic duo, as Fischer notes they "would not stop improvising" during the shoot. "We were milking it," she says.

After such a positive experience with her former costars, Fischer says: "I want to do another AT&T shoot and I want to have even more people pop in. That would be my dream."

Related: Jenna Fischer Says Fans of The Office 'Don't Understand' That She and John Krasinski Aren't a Couple

"I don't know how to make that happen," she continues. "But I mean, truly that was so much fun and we were getting to have our comedic chemistry without having to worry about, 'Are we messing up the story and the lore of our characters of The Office?' So the AT&T commercial gave us an opportunity to work together again in a really beautiful way."

Although AT&T Business only wrangled some of the cast for its fun-filled campaign, the entire cast — which includes Steve Carell, John Krasinski, Mindy Kaling, B.J. Novak and Ellie Kemper — still keeps in contact very regularly.

"We have a text thread. It's called Office Peeps, and we all text on it, send pictures and updates and all the things you have on a text thread," she reveals. " We just have our text thread. But then, we all run into each other and get together on the side. But we have our text thread, it's going strong."

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer​​, from celebrity news to compelling human interest stories. 

The Office can be streamed in full on Peacock.

For more People news, make sure to sign up for our newsletter!

Read the original article on People.