Young Sarah Michelle Gellar Wouldn’t Believe She’s Working with Christian Slater, Patrick Dempsey (Exclusive)

Sarah Michelle Gellar‘s latest role definitely checks a major bucket list item off her list.

The actress stars in Dexter: Original Sin alongside Christian Slater and Patrick Dempsey, and while she may seem like she’s keeping her cool about the all-star cast, she tells PEOPLE how she really feels about working with some fellow ’90s icons.

“I can’t lie, if you went back to high school Sarah and said that you’d be sitting in a car squished between Christian Slater and Pat Dempsey… I mean, forget about it,” Gellar, 47, says, before calling her costars by their Heathers and Can’t Buy Me Love characters’ names. “Ronald Miller and JD? Forget it.”

She continues, “It’s funny because it wasn’t Grey’s Anatomy for me, it’s Can’t Buy Me Love. That is a classic — a classic. I used to want to be Amanda Peterson.”

After hearing that his role as Ronald Miller is what Dempsey, 58, has said he’s recognized the most often for, Gellar is unsurprised. “I would think so,” she says. “I mean, at least in my heart.”

Despite her love of Can’t Buy Me Love, Gellar admits that it was Slater’s breakout role that really had a chokehold on her.

“Heathers was — and Christian knows this — was my all-time favorite movie in, I think, the world,” she says.

Slater, 55, is aware of it, too. “I mean, Christian and I know each other, so I think Christian knows my feelings about Heathers.”

The feeling is mutual on Slater’s side. “She’s the coolest,” he tells PEOPLE of Gellar. “She was always lovely and very complimentary”

“She might’ve said that she had a crush on me at some point in her life,” he continues. “But God, I mean, I love her too. She’s amazing.”

Crushes aside, Gellar praises the whole cast of Dexter: Original Sin — which sees the titular serial killer as a 20-year-old just beginning to explore his deadly urges, with Patrick Gibson taking on the role of a younger Michael C. Hall.

“This cast gelled in a way that I’ve — you know, I’ve been doing this a very long time — I’ve never experienced,” she says. Gellar stars as Tanya Martin, the CSI chief at the Miami Metro Police Department, where Dexter starts working after college graduation. His dad Harry Morgan (Slater) also works there as a detective with Aaron Spencer (Dempsey), the Miami Metro Homicide Captain.

“And I think it came from the fact that a lot of us have worked all the way through… Paddy’s a child actor, he has worked all the way through, and so everyone came with this sense of, ‘Let’s do this. Let’s kick butt, but let’s also go home,'” she says of the cast’s dynamic on set.

“Nobody was late. Everybody knew their stuff. It was such the experience you hope to have.”

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New episodes of Dexter: Original Sin premiere Fridays on Paramount+ with SHOWTIME Plan.