Temperley London “Fern” silk-chiffon and embellished tulle gown, $3,170 at net-a-porter.com; white floral faceted crystal earrings, $395 at Oscar de la Renta, 772 Madison Ave.; “Heirloom” gold and crystal necklace, $420 at lulufrost.com; “Mademoiselle” necklace, 178 at Henri Bendel, 712 Fifth Ave.; Vionnet cuff, $900 at mytheresa.com; Ralph Lauren Collection ostrich cape, $2,498 at Ralph Lauren, 867 Madison Ave.

Super siren

“Avengers” actress Cobie Smulders soars in blockbuster deco fashions

By JOHANNA SCHNELLER

If Cobie Smulders sounded slightly hungover on the phone from Los Angeles, at least she had a lot to celebrate. A birthday dinner the previous night with friends. A lead role on the hit series “How I Met Your Mother,” whose audience numbers are, incredibly, growing in its seventh season. A happy home life with her partner of seven years, actor and “Saturday Night Live” regular Taran Killam, and their 3-year-old daughter, Shaelyn. And a blockbuster poised to explode, “The Avengers,” in which she plays right-hand woman to Samuel L. Jackson. Now, that’s the way to turn 30.

“My daughter wakes up at 6:30, so I have two people touching me right now, trying to make me look like I had more than five hours’ sleep,” Smulders says from the makeup chair at the photo shoot for these pages. Luckily, thanks to “HIMYM” (as her show is often called), she can handle physical comedy — while trying to talk and be primped at the same time, she suffers a mascara wand in the eye, and gets inadvertently intimate with her hairdresser. “Sorry!” she says to the latter. “Did I just touch you in the special spot?”

In “The Avengers,” due out May 4, Smulders plays Maria Hill, a “tough-as-nails” agent in SHIELD, a kind of CIA on steroids. “She takes care of business,” Smulders says. “She gets stuff done. And she tries to control everything.”

To get catsuit-ready, Smulders worked out with a black-belt-level weapons specialist who trains SWAT teams. He took her to a shooting range, introduced her to all things gun-related and taught her evasive maneuvers. “I loved it,” she says, sounding giddy. “I was boxing three times a week. I felt like a total badass.” In fact, she got so into character that whenever Maria had to shoot someone, Smulders would volunteer, “Can I just shoot him two more times, make sure he’s dead?” she remembers, chortling. “The whole experience was like I jumped on a springboard. Everything about this movie was big: the sets, the crew list, the special effects. I left the screening feeling, ‘I’m so proud to be a part of this.’ I really think the fans are going to freak out over it.”

Meanwhile, on the small screen, “HIMYM” is enjoying one of its strongest seasons to date, thanks in part to an influx of new fans who are catching up with the story via Netflix and repeats. Smulders’ character, Robin, a driven careerist, is a straight woman with a twist: Her former life as Robin Sparkles, an ultra-peppy Canadian teen pop star, was revealed awhile back in spot-on mock-videos with titles like, “Let’s Go to the Mall” and “Sandcastles in the Sand.” (Smulders, who was born and raised near Vancouver, dives gamely into the show’s frequent jokes about beavers, canoes and the pronunciation of “aboot.”)

“I’m so blessed,” she says. “I get to do these wacky things, like dance numbers in the street with all these extras dressed in suits, and also these amazing emotional moments.”

This season, for example, Robin found out she can’t have children. “It’s cool to bring that to light, because I know so many women who are having issues,” Smulders says. “Before, Robin was always hard-edged, ‘Love is stupid, don’t be sappy.’ Now she’s more humanized and vulnerable. We could just do setup-setup-punch line, have [Neil Patrick Harris’ character] Barney put on another costume and try to pick up a girl. Instead, the writers choose to do stories that are relatable, and hopefully people are moved by it.”

The characters’ close dynamic on-screen is the same for the actors off-screen, Smulders says: “Everybody is really cool and down to earth. We’ve had babies together, ups and downs. Both my and Alyson’s kids turned 3 this year,” she says, referring to co-star Alyson Hannigan, who plays sweet-faced, dirty-minded Lily. “And it’s like, ‘What?!’ Starting this next chapter together has been really wonderful.”

Especially since the eighth season could be the last, she adds. “Who knows? But that’s where our contracts end.”

Whatever happens with the show, it’s unlikely that Smulders will return to modeling, which she did in her teens and early 20s before becoming an actress. At 16, she spent a summer in Japan doing catalog and beauty modeling. “My friends were at camp, and I was in Tokyo,” she says. “It was total culture shock.”

After graduating from high school, she moved to New York to continue modeling, but her heart wasn’t in it. “I was definitely using it to live in the West Village for free, to go to Paris or Germany for six months,” she says. “But it had an expiration date.”

At her one and only runway show, she tripped and fell flat on her face. “It was a shoe issue, and also I think the runway was just tables stuck together length-wise,” she says, laughing ruefully. “It was all very wobbly. I didn’t enjoy making a living off of how I look, so I bowed out.”

Modeling did teach Smulders what she looks good wearing, however. Currently, she favors labels such as Rag & Bone and Elizabeth and James, “designers who are good at mixing feminine and masculine together,” she says. “You usually find me in jeans, and I have so many navy blazers. I have 40 blazers in my closet, for every occasion. I think it’s a really good go-to — you can throw it over jeans or a dress.”

One gown at this photo shoot got her drooling, however: the Carolina Herrera number with vines across the back. “If I ever get to the Oscars, I’m going to find that dress and wear it,” she says.

Despite the threatening mascara wand, Smulders sounds remarkably calm and sane. “I’m in a really good place,” she says. “I’ve experienced a lot. I don’t have anything that’s unfulfilled. I have multiple wonderful jobs, and I’ve got a great home and family. I welcome turning 30. I’ve always felt older than I am, and now I feel like I’m my age.” She’s in a special spot all right, and, “It’s really nice.”

All deco’d out at the Hollywood Roosevelt Hotel

For affairs to remember, clandestine or not, stay at the ultra-glam Gable & Lombard Penthouse at the Hollywood Roosevelt Hotel named for infamous lovers Clark and Carole whose secret rendezvous spot was at the legendary LA institution. Redesigned in 2006 by designer Dodd Mitchell, the 3,800-square-foot, three-floor modern suite oozes allure in details like mirrored accent walls, plasma televisions and a wet bar. Star quality seduces outside, as well as on the 1,000-square-foot private roof deck with stunning ocean and city views. It’s where you’ll find Alexa in Tinseltown.

Photos: Victoria Will

Fashion Editor: Serena French

Stylist: Anahita Moussavian

Makeup: Coleen Campbell/ Exclusive Artists, LA

Hair: Davey Newkirk/ Tracey Mattingly, LA

Location: Gable & Lombard Penthouse, Hollywood Roosevelt Hotel, Los Angeles.