Is there any bigger affront to the most stylish 14-year-old girl in Hollywood than having to wear a kilt to school? Done in a traditional tartan, it’s part of the uniform at Campbell Hall, Elle Fanning’s private school in the San Fernando Valley, where it’s paired with a polo or blouse in white and navy (seniors may add two colors) and a navy overcoat (all jackets, including hoodies, must be navy). Fanning—co-star of films like Super 8, We Bought a Zoo, and the upcoming BFF-betrayal indie Ginger & Rosa—likes to wear her skirt short, but not too short, on her “five-seven-and-three-quarters” frame, and who’s to say what’s short anyway? “The kilt’s supposed to be long enough that your fingertips can reach the ends [when you’re standing]. But what if someone has extra-long or extra-short arms?” she says, giggling.

At home, Fanning keeps her Campbell Hall clothes separate from her going-out clothes, things like Prada geisha shoes, loose Céline pants, and floor-sweeping dresses by the Rodarte sisters, for whom she has been a muse. “I have a sliding glass door on my closet,” she says, “and when I slide it one way I can see all my uniforms, and the other way is all my own clothes.” And, of course, she can make a kilt work if she has to. Today, arriving at the cozy, buttercream-scented headquarters of Duff’s Cakemix, a “cake-decorating studio” in Hollywood, she’s accessorized with maroon Alexander McQueen ballet flats with a brass skull medallion at the toe (a tweak on conservative staples like Tory Burch’s), a stack of diamond and ruby rings (loaded up on her ring finger like a middle-aged woman’s anniversary bands), and two gold chains. “I like necklaces that are short, the way skateboarders used to wear them in the seventies,” she says, touching the one that hangs a bit lower than the other on her alabaster neck.

In the L.A. tradition of paying someone to handle a project you don’t feel like doing, this bakery provides premade cakes for customers to decorate with tubes of icing and fondant in many different colors—the fun part of baking, without the mess and stress. The choice of frosting a cake while conducting an interview today seems less about dessert or providing a colorful scene for a writer than making sure she doesn’t become restless with only one task at hand. Fanning’s blue-eyed gaze is fiercely intelligent, and it makes you feel like you’re in the presence of a hyperactive mind, even if she still looks like a kid. Despite her role as a fashion icon, anointed by Anna Wintour and the rest, she’s gawky in the way that many tall teenagers are—as if someone had run a rolling pin over the 12-year-old version of her, doubling her height. I also notice a name written in pen on her wrist: BOB DYLAN. “I write it on my hand every day in school, mostly when I’m bored,” she says. “I’ve been doing it since I was pretty young. I used to do it for fun, but now it’s a nervous tic.”

While keeping up a conversational patter, Fanning eyeballs her slab of cake, cutting a neat teddy bear out of fondant and starting to stir pink dye into her glob of icing. “Yesterday,” she says, “I went to the vintage store Wasteland with my grandmother to look for clothes. People say it’s so hard to look in there, because there’s so much, but you really just have to focus, get in the zone.” She smiles triumphantly. “I found this amazing floral jumpsuit that’s so cool. I have the patience to look through every rack.”

Fanning likes talking about fashion. Her mother, a Southern belle partial to Peter Pan collars, dressed her daughters in Bonpoint as kids—Fanning, funnily enough, says that she likes to shop for clothes for the children she wants to have someday. She’s a pack rat, she adds, and not just when it comes to clothes. She and her family have about 80 Madame Alexander dolls and a collection of Care Bears, and she keeps a lot of stuff like old wishbones in her bedroom. Fanning lives in the Valley with her parents; her sister, Dakota, moved out in 2011 to go to NYU. The family has been in Los Angeles since 2001, when Dakota, then 6, was cast as the daughter of a mentally disabled Sean Penn in I Am Sam. The film ended up as Elle’s first acting job too—she put in a few days on set to play the younger version of her sister. She was 2.

By 2004, Fanning had her own role in The Door in the Floor, with Kim Basinger and Jeff Bridges. “One of my earliest memories is Jeff teaching me how to draw,” she says. “Instead of drawing a triangle for a dress and two sticks for legs, the way most kids do, he told me to draw four lines and connect them at the bottom so the drawing would look fatter.” She now considers film roles her “after-school activity,” and likes to learn lines for her movies at night in the bathtub, making the water very hot and scenting it with Mr. Bubble. “I like playing characters with as many emotions as possible,” she says. “I’d love to play a really crazy person—someone truly out of her mind.”

Fanning clearly has a sophisticated visual sense, and not only because her teddy-bear cake, decorated with orange and red balloons and an outline of blue icing, ends up making mine look like I frosted it with a baseball bat. She likes photography and biology—two more fields that are often taught schematically—and seems to consider fashion her other after-school activity, after acting. (Let’s not even talk about ballet, which she also studies seriously.) “At night, after homework, I check out what’s going on in the fashion world,” she says, nonchalantly. Right now she’s really into eye shadow—she tried out a pink one recently, because “I was inspired by the Chanel resort show, where the models had on different pastel wigs, and I wanted to do my take on a sixties eye, but with pink.”

Fanning has always loved dressing up: At 7, when she decided that she wanted to buy Marilyn Monroe’s powder and face cream at an auction, she went to the preview in a wig and a copy of the white dress from The Seven Year Itch. But her interest in fashion is deeper than costumery. She might not be the type of person who has a hard time expressing herself, but she enjoys being able to telegraph her individuality, her perspective on the world. “For a long time,” she says, packing up her cake in a white cardboard box, and referring to an amount of time that I have to guess was measured in months, “I refused to wear jeans. I liked high-waisted pants, but jeans made me feel like I wasn’t being unique.” She makes her way out the door, off to study prefixes and suffixes for a Latin quiz. “Even now, I won’t wear the skinny-jeans style, because most people wear those—they have to be baggier, boyfriend-looking, or sort of like a mom jean. I’m real funny that way.”

*This article originally appeared in the February 18, 2013 issue of New York Magazine. [Source]