"It was hard because we were so jokey with each other, so much of the time it was pretty tough not to crack jokes. But it was really cool to do something different with him," she adds.
Stone, whose stunning designer wardrobe for The Amazing Spider-Man world tour won her the title of best-dressed celebrity from fashion bible Vogue, lives up to her reputation in person, showing off her long legs in a black lace skirt, teamed with matching top, monochrome jacket and heels.
In Gangster Squad she portrays actress Grace Faraday, who is dating maniacal Mafia gangster Mickey Cohen (Sean Penn) while secretly sleeping with Gosling, who plays LAPD detective sergeant Jerry Wooters.
Playing a fictional femme fatale had its challenges for Arizona-born Stone, who rose to fame playing kooky roles in teen comedy Easy A and Zombieland, before starring in The Help and The Amazing Spider-Man.
"I've always been really attracted to characters who are very self-assured, confident and don't need a man to validate them, but I think there was something in me that was interested in what the flipside is," she explains.
"Grace needs validation, she needs something from a man. She wanted to be a star and settled for being famous by proxy with a dangerous man, and falls in love with Wooters when she needs protection and he's sweet to her.
"She's got a pretty sensitive, insecure constitution underneath that manicured veneer, so it was interesting."
She considers it her most grown-up role to date: "Grace has already been through stuff that makes her a woman. It was nice, I do feel like a woman. I can say that for the first time."
She also enjoyed her glamorous 1940s outfits, saying: "The clothes were very silky and lovely, but I don't know if I would be comfortable in these gowns in real life. But it was definitely a lot of fun to play dress-up."
Stone, who changed her name from Emily after realising there was already an Emily Stone registered with the Screen Actors Guild, also relished the opportunity to share screen time with Penn.
"I really admire him as an actor, so I was more excited than anything to work with him. He was not intimidating," she says.
"The best thing about him is the fact he can flip in and out of a character, he can just turn it on and off. He doesn't have to stay in character in between takes, unlike me."
Stone admits to sharing some kookiness with her screen characters.
"You should hear all the crazy in my head. I've got a voice in my head that says, 'Hey, oh my God', all the time. I still feel like I'm insane. And I drink too much coffee," she jokes.
She may be the go-to princess for comedy, but the actress is intent on stretching her skills.
"Comedy's my true love. I don't think anything will ever compete with that for me," she says. "But I've been lucky to have the opportunity to do things out of that wheelhouse because I'm very interested in all different aspects of being an actor. And as I get older, I can understand different parts of the psyche in different ways," she continues before deadpanning: "Because I'm really so old now. I'm like 140 years old."
Stone's winning red carpet looks on the Spider-Man tour, which stopped off in Rome, Madrid, Berlin, Seoul and Tokyo, has bumped her up in the style stakes. Along with the Vogue honour, she finds herself in the front row at fashion shows and has top fashion labels clamouring to dress her.
She's quick to laugh off her status as the new fashion darling, however, saying: "It's pretty funny. It's hilarious and fun to be around because it's just so different.
"I am a person who is very lucky to do what they really love to do, which is to act. That's a really fun job and all the other stuff, especially after the Spider-Man tour, has become really funny."
Aside from fashion and films, Stone likes baking, watching documentaries and TV shows (she's currently into comedies Girls and New Girl) in her spare time.
"I don't cook that well. I can bake, but cooking, I haven't really tried my hand at very often. I can bake anything, I can do it all," she quips. "As an actor, you work for three months, then you don't do anything. I haven't worked since Gangster Squad so I've been able to take some time and see what happens when I don't do anything. And I can say, it's not good! You can see people you want to see, travel around, do a little bit of reading, and spend way too much time getting lost in the internet. Once you start, it's like a black hole," she adds, laughing.
Looking ahead, Stone is set to reprise her role as Gwen Stacy in The Amazing Spider-Man sequel, and work with Cameron Crowe and Bradley Cooper on an as-yet-untitled film.
Who: Emma Stone
What: Gangster Squad
When: Opens at cinemas on Thursday
- TimeOut / AAP
