On Friday's episode of the PEOPLE Every Day podcast, the Quest for Sleep narrator, 52, shared
"I can tell you that Will is definitely not an adult elf," Spencer joked to host Janine Rubenstein, in reference to the actor's previous smash-hit holiday film. She then added that that the SNL alum is "one of the smartest people I've ever worked with."
The Oscar-winning actress joined Ferrell, Ryan Reynolds and Sunita Mani for this season's Spirited, and had just as much fun making the musical comedy (based on A Christmas Carol) as you'd imagine — though she definitely felt the "pressure" to bring the laughs. "When you're opposite people like ... Ryan and Will, I can say it can be a little intimidating," she says. "But I had so much fun doing it!"
She commends the "brilliant writing team" for a much-needed film that "brings joy" and "an amount of escapism for people right now."
As for Spencer and Ferrell's friendship, it appears the admiration is mutual, as Ferrell, 55, was on hand to support Spencer at her Hollywood Walk of Fame star ceremony on Dec. 8. He even shut down a heckler who tried to interrupt his speech by declaring, "Not on Octavia's day!"
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Spencer also discussed another project of hers, a documentary called The Quest for Sleep, and explained why it was so important to her.
RELATED VIDEO: Will Ferrell Shuts Down Heckler at Octavia Spencer's Walk of Fame Ceremony: 'Not on Octavia's Day!'
"I don't have a good relationship with sleep. I never have. It's affecting me now," she said. "In my business it's sort of a badge of honor to say, 'I didn't get any sleep last night.' And I was hearing that across several industries and I thought, 'We need to start prioritizing our sleep. Sleep is elemental and integral, you know, for survival."
As is laughter! PEOPLE caught up with Spencer on the carpet for the Nov. 7 Spirited premiere, and when asked how she kept a straight face shooting with comedic icons like Ferrell and Reynolds, she said, "You know what? That's the thing. You don't have to."