In the 1961 film Breakfast at Tiffany’s, Audrey Hepburn’s character, Holly Golightly, muses that a visit to the jeweler’s Fifth Avenue flagship store “calms me down right away. The quietness and the proud look of it.” She continues, in these lines also found in Truman Capote’s novella of the same name, that “nothing very bad could happen to you there.”Turns out, Golightly was right. I discovered this firsthand when I inadvertently knocked over a piece of Tiffany china during a visit to the Blue Box Cafe, the luxury retailer’s first dining venture, located on the fourth floor of the famed location.The crash was neither quiet nor proud. I was mortified, and I know my middle school self — who coveted Tiffany’s chunky sterling silver jewelry beyond any school crush — would have been, too.But instead of a proper scolding, my waiter nonchalantly whisked the broken crockery away. “It happens more often than you’d think,” he explained. His gaze shifted to another diner, who was struggling to hoist his heavy digital camera over his $70 Tiffany blue dinner plate.He looked back at me and smiled: “Just don’t let it ruin your experience.”The concept of “Breakfast at Tiffany’s” has changed dramatically since Golightly’s tranquil 5 a.m. stroll down Fifth Avenue in her sleeveless black dress. Now, instead of paper coffee cups and curbside pastries, modern-day Golightlys can indulge their rich fantasies with a three-course breakfast inside the store.Visiting the seemingly built-for-Instagram restaurant, which opened to fanfare in November of last year, has become a bucket-list item for foreign tourists, film fans and even New Yorkers. The photo-friendly spot, outfitted entirely in the brand’s signature robin’s-egg blue and white, was reportedly designed with the intention of having guests feel like jewels nestled in one of Tiffany’s trademark boxes: A reservation at the compact cafe, which seats only 40 people, has become as desirable as one of the jeweler’s heart-tag charm bracelets.During a quick trip to the Big Apple in May, I was lucky enough to snag a last-minute weekday lunch reservation online. I arrived early to get the lay of the land and, in the spirit of Golightly, allow extra time for window shopping. Visitors must navigate the store’s bustling first floor — a maze of eager employees, shiny display cases and ogling tourists — to reach the elevators leading to the cafe, which are manned by white-gloved attendants. En route, I stopped to gawk at a whopping 128.54-carat yellow diamond. (By comparison, the famous blue Hope Diamond is just over 45 carats.)I then made my luxurious ascent to the fourth floor, where the cafe is perched at the end of the home-and-accessories department. Nothing makes a person feel more cognizant of their income — or lack of it — than passing by a $125 bone-china dog bowl and a $400 mohair teddy bear.At the host’s stand, I received the royal treatment, despite my lack of tiara and satin gloves, and was whisked to a two-top table facing Central Park’s Grand Army Plaza. Many restaurant guests had dressed for the posh occasion in fancy fascinators and black cocktail dresses. One group of women, clad head to toe in blue, even bragged to their waiter that they had gotten matching teal mani-pedis the night before.From the walls to the slipcovered chairs and leather-bound booths, the space was a veritable sea of Tiffany blue. The attentive and friendly staff even sported blue ties and aprons.The menu was full of trendy American fare (avocado toast) with buzzy New York monikers (the Fifth Avenue salad, with Maine lobster and grapefruit). And though I arrived at noon, I ordered breakfast, which is served all day. The decadent meal included a seasonal fruit plate with edible flowers and pre-peeled grapes; a miniature croissant with three spreads (Nutella, butter and jam); and my choice of one of four entrees. I opted for the smoked salmon and crisps — basically a deconstructed lox bagel.While the food could coast on the Tiffany name and nostalgia alone, the cafe delivers in terms of presentation and flavor: The fruit was fresh, the croissant buttery and flaky. And the bagel crisps featured a generous portion of fresh lox. I savored every bite during my leisurely, hour-long meal.Sipping my second cup of coffee and staring out at the city’s natural gem, Central Park, I was tempted to start humming Moon River. However, this serene moment was interrupted by a gaggle of giggling Golightlys, staging a full-blown photo shoot with a pastry shaped like a miniature bird’s nest. “Get one of me with the sunglasses on!” one of the bouffants bellowed to her smartphone-wielding seatmate. Despite the quiet and proud bones of this place, it is still susceptible to enthusiastic selfie seekers who want to preserve — and, perhaps more important, share — their fine memories of this special place.Susceptible to my neighbors’ enthusiasm, I decided that I, too, wanted a memento. I set my purse on the table, snapped a final photo of the tablescape — and clumsily bumped the white china creamer off the table.Instead of pocketing a shard of Tiffany china, I asked my waiter whether I could keep a cardboard coaster as a keepsake. He smiled, then returned with a second.I guess everyone channels Golightly’s spirit in their own way. The Blue Box Cafe, in the Tiffany tradition, makes a world of luxury and glamor accessible to all — even if only for breakfast.