Gerstner K. u. K. Hofzuckerbäcker

The pastry kitchens are the engine room here. Every morning, they turn out the kind of sugar-work that won them an imperial warrant in the 1800s. Check the ground-floor boutique cases. You'll see rows of neon-bright macarons, tiny petits fours, and hand-dipped truffles. Coffee arrives the proper way. Expect a silver tray and the mandatory glass of water. Order the Wiener Melange if you want what the locals drink. It's a smooth mix of espresso and steamed milk. If you're feeling indulgent, get the Wiener Eiskaffee with vanilla ice cream and a mountain of whipped cream. Pairing your drink with cake isn't optional (it's the whole point). Try the seasonal fruit tarts or the candied violet petals that Sisi loved. Every bite is a lesson in Viennese sugar craft.

You're eating inside the Palais Todesco, a 19th-century powerhouse of a building. The space spans three floors. Each level has a different vibe. The ground floor is a fast-paced shop for boxed gifts. Head upstairs for the slow stuff. The first-floor café-bar has crystal chandeliers and views straight onto the State Opera. It's the best spot in town for a pre-show drink. The second floor is the formal restaurant. Look up at the painted ceilings and gold leaf accents. Anton and Barbara Gerstner started this empire in 1847. They catered the biggest banquets in the Austro-Hungarian Empire. You can feel that weight of history in the quiet hum of the rooms and the clink of heavy porcelain. It's grand without being stuffy. But it definitely feels like an occasion.

The menu is huge. Don't get overwhelmed. Start with the Sachertorte. It's dark, dense chocolate cake with a sharp hit of apricot jam. The Apfelstrudel is another winner. Ask for it warm with a lake of vanilla sauce. The pastry is stretched thin enough to read a newspaper through. If you want lunch, go for the Wiener Schnitzel. They use veal, not pork, and the breading is light and airy. For something smaller, grab the elegant tea sandwiches or a bowl of beef soup with semolina dumplings. It's the ultimate winter fuel. The bar is excellent too. Skip the standard sodas and try a local Austrian wine or a glass of Schlumberger Sekt. Before you walk out, buy a tin of candied violets. They're the same ones the Empress ate.