The naked truth about Lara Pulver

Just to be clear, Lara Pulver was not completely naked in that Sherlock scene. "No. I was wearing Louboutin shoes. Earrings. Make-up. And this weird kind of…" She cups her hand and stares at it, baffled. "I don't even know how you'd describe it. Cup? A cup thingy." She hoots.

It took a "skeleton crew" of eight people six hours to shoot the moment when Irene Adler greets Holmes and Watson without a stitch on. The instant that filming was over – "such a relief" – Pulver wolfed down a Snickers. A Snickers! The dominatrix who steals Sherlock's heart is just like us! "But it was one of those Celebrations mini Snickers and I had to share it with the wardrobe girl." Oh.

As she sat there in a robe, scoffing her tiny treat, Pulver had no idea that the 111-second scene – which would be watched by nine million people on New Year's Day 2012, and a further 2.5 million online thereafter, making it BBC iPlayer's most watched of the year – was about to change her life. Over the previous decade, she had starred in everything from Miss Saigon and Sondheim to True Blood and Spooks, but it took a flick of Irene's whip to send her stellar.

"The only way I could describe it is that it's like that bit in The Wizard of Oz where everything goes from black and white to Technicolor. Everything was OK beforehand – it was great – but all of a sudden, the lights had come on," she says. "The last year has been extraordinary."

Now, at 32, Hollywood is "opening up" to her. In the meantime, she is starring in BBC Worldwide's new transatlantic blockbuster Da Vinci's Demons, written by David S Goyer, who wrote the Dark Knight trilogy. She plays Clarice Orsini, muse to the young artist and inventor, wife of Lorenzo de' Medici, and "the rock behind the throne – the Kate Middleton, the Hillary Clinton, the Jackie O…" And she is currently filming Fleming, a "wonderful, twisted love story" for Sky Atlantic in which she plays the author's wife, opposite Dominic Cooper. The original Bond girl? "There's a quote: Ann O'Neill was the only woman Ian Fleming ever went to bed with – and woke up next to."

Both roles offer more raunch. The Flemings had a penchant for whips, Da Vinci's Demons is a historical romp in the mould of Rome and The Borgias. Does she worry about being typecast as a vamp? In the flesh, she is almost absurdly glamorous – an alpha mix of cheekbones and dark curls and dressed today in violet lace-up boots and a tweed riding jacket. "Initially after Sherlock I got offered a lot of swinger movies," she admits. "There is that thing of keeping your mystique, and not taking your clothes off in every job. Sometimes as an actor you have this overwhelming sense of wanting to please… If it feels right, there's no problem doing it. But I'm looking at the long term and that's not my focus."

But first, back to that scene. Did she really, as Sherlock's creator Steven Moffat claimed, send in a naked audition tape? "No! Well, I was wearing a maxi dress, so you could see décolletage, shoulders… I emailed Steven about that and said, 'Now every actress in the world is going to think she has to send in a naked tape to get a job' – horrible." Did she find stripping on screen "empowering", as she said at the time? "Not empowering to take my clothes off in front of other men, or for the character… I meant that I went on set and didn't crumble. I, Lara, was still able to do my job. I didn't forget my lines or become flustered. All of a sudden the body, the vehicle I've been given to be in on this planet, just became inconsequential." How did she feel about the 100 complaints to the BBC? "That was ludicrous," she says. "You saw more of Benedict [Cumberbatch] when his sheet fell down than you did of me."

All of the excitement was tempered by heartbreak, as her divorce from the American actor Josh Dallas came through at the same time. They met on The Boy Friend at Theatre Royal, Windsor 10 years ago, married in 2007 and moved to LA in 2009.n "Professionally, it was this ultimate high, and personally, the carpet had just come out beneath my feet. I didn't know where I lived, I didn't have a job and I didn't have my partner in crime, with whom I so wanted to share this moment. I chose to look in the mirror and say, 'What do you want, Lara?' My eyes opened. So I'm actually grateful for the most painful time in my life."

She decided to stay in LA, post-divorce. It suits her and she has soaked up a little of California's can-do attitude. She talks about "Lara" quite a lot and says things like, "Hollywood execs that I've met post-Sherlock have all said that there are only a handful of people they feel have the talent, the skill and the strength to play that kind of powerful, sexy woman who can also turn vulnerable within seconds." It's quite refreshing to meet a British actor who doesn't even pretend to be self-deprecating. "It's lovely to be excelling in life and in my work and be around that mentality of anything being possible," she agrees.

It's quite a different Lara from the geeky little girl who was packed off to audition for a local am-dram Annie one summer. Her father, an insurance salesman, and mother, who worked at Barclays, were splitting up at the time and wanted to keep her busy. She won the lead but at Dartford Grammar School for Girls she was more interested in sport until she joined the National Youth Music Theatre. By the time she was 16, she had toured to the Far East and Broadway and was weighing up drama schools. Going to West End shows as often as her mother could afford it, she would comb the programmes, tallying up who trained where. "I literally had a chart."

She settled on the Doreen Bird College of Performing Arts and embarked on a decade of musicals. In 2007, she was Olivier-nominated for Parade at the Donmar Warehouse. When the show transferred to LA, she went too and was spotted by Alan Ball, who signed her up to play Claudine in True Blood. From there she joined Spooks, as section head Erin. "I was the ultimate action girl, leaning out of reversing cars with a Walther PPK." Did she do her own stunts? "Yeah! It was brilliant. Chris Fry, the producer, said, 'The wonderful thing about casting you is that you're so physically capable. We can have a real kick-arse girl in MI5.'" She didn't know until three-quarters of the way through that it would be the final series. "That was… bittersweet."

She is now dating Raza Jaffrey, who played Zaf in series three to six of Spooks. They were friends in LA for three years before she asked him out. Having just divorced another Spook, Miranda Raison, he told her politely that he didn't date actresses but a year ago, that went out of the window. "We're a very normal couple but there's an element of our job that involves a bit of sparkle and glamour," she says. "But we're also paying our electricity bill and doing the food shop."

They live in the Hollywood Hills – though they are rarely at home. "There's a standing joke: how many cities are we going to wake up looking at?" Fleming has her shuttling between Budapest and London. Has it given her a taste for being a Bond girl? "Gosh, I'd never say never to dipping my toe in that water." She has already been touted as the first female Time Lord. "I would definitely talk to Steven [Moffat] about it. A female Doctor Who… who knows?" She won't, though, return for the third series of Sherlock. "But you just never know with those guys. They said they hope to continue doing it for another 20 years. If that happens, it would just be wonderful."

She has a lot to thank Irene Adler for, after all. "You work for 10, 15 years, then one job just…" she beams. "And you know it's not one job, it's the 10 years of work you've done prior to that. But Sherlock really changed the game."

'Da Vinci's Demons' is on Fridays at 10pm on Fox