Tiers of joy: layered trays of cupcakes at Georgetown Cupcake in Washington, D.C. (Andrea Lee/CBC)

The hotcake might want to watch its back: it's the cupcake, these days, that's selling fast.

At least, that's the case in Georgetown, a tony neighborhood in northwest Washington, D.C., where, on a recent Saturday morning, more than a dozen customers lined up on a quiet street outside a cupcake bakery waiting for the doors to open at 11 a.m.

It is not an understatement to say that Georgetown Cupcake has taken Washington's cupcake scene by storm.

Canadian sisters Sophie LaMontagne and Katherine Kallinis, who grew up in Hamilton, opened the bakery in February. Kallinis, 29, a politics grad, was an event planner for Gucci; LaMontagne, 31, who'd studied molecular biology in university, worked in private equity.

But as teenagers they'd spent countless hours in the kitchen with their maternal grandmother, and baking was their passion.

"We believed in it," said Kallinis. "We just had a dream and we followed it."

It wasn't easy, and the sisters "didn't think it would take off." They worked seven days a week, baking and frosting cupcakes, making coffee, working the cash, doing the cleaning, stocking inventory, and paying the bills.

Ten months later, Georgetown Cupcake is D.C.'s most popular "cupcakery." It has a staff of 50, routinely sells thousands of cupcakes a day and has a bustling catering service. It's also been featured on NBC's The Today Show¸ The Martha Stewart Show, National Public Radio, and in The New York Times and The Washington Post.

Worth the wait

It's thanks to that kind of exposure that more than a dozen people were risking their own exposure in freezing temperatures just waiting for the bakery to open.

By 10:50 a.m., four women in their 50s huddled together in winter coats, toques, earmuffs and scarves. A woman in her 20s — a student, perhaps? — stood with her shoulders hunched in a green ski jacket, a black toque pulled down low over her ears, and turquoise plaid pyjama pants tucked loosely into sheepskin boots.

Saturday morning lineup at popular bakery Georgetown Cupcake in Washington, D.C., owned by two Canadian sisters (Andrea Lee/CBC)

One man stood out, in a grey sweatshirt, running shoes and black shorts.

"I just came from the gym," he explained to the woman in front of him.

At 10:59, a bearded man in a ball cap scanned the line. "This is a short line," he said.

"This is the shortest line it's ever been!" agreed the man from the gym.

An elderly woman in front of him stepped side to side, as if to keep her feet warm. "I'm going to get a mocha one," she told her friend. "Mocha sounds good!" he answered.

A young blond woman finally opened the doors: the bakery was open for business.

"Good morning, everyone!" she called to those in line, who slowly, thankfully filed inside.

Tiny work of art

Walking into Georgetown Cupcake is like walking into a freshly baked cake. It is warm, comforting, and smells of chocolate. It is small, with room for just one table and three chairs, and the staff is friendly. At this time of year, Christmas music plays over the sound system.

Top-selling cupcakes at Georgetown Cupcake in Washington, D.C. (Andrea Lee/CBC)

The cupcakes are prominently displayed on three-tiered cake trays on a large granite counter. Behind the counter there are stacks of small, medium and large pink boxes that, one by one, get filled as the orders come in.

Each cupcake is like a tiny work of art. There is the mocha (chocolate cupcake, mocha icing, topped with a chocolate-covered espresso bean), the lemon berry (light lemon and raspberry cupcake, raspberry frosting, candied lemon peel), and Georgetown Cupcake's signature cupcake, the red velvet (light chocolate cupcake, vanilla cream cheese frosting, red fondant heart.)

They are small and fit neatly in the palm of the hand. LaMontagne describes them as "not huge, not gigantic things that make you feel disgusting afterwards."

Some might question the long-term prospects of a single-product bakery. But Kallinis calls the cupcake "an American classic dessert. People say it's a trend, but they've been around forever."

At this rate, so might Georgetown Cupcake.