Mexico City Specialty

Establishment neighborhood
Churros El Moro
Eje Central Lázaro Cardenas 42, Colonia Centro
This legendary "churreria" has been open in the same locale in the Centro since 1935 when the Spanish owners bought the property and imported the Spanish fried-dough delicacy to Mexico. They've been going ever since, in the same old building, with floor to ceiling tiled interiors, and the same menu of churros and four hot chocolate varieties—the thick Spanish version, traditional French style, cinnamon and vanilla-infused Mexican variety, and Swiss, which comes with whipped cream. There are a couple of new specialties on offer, including their take on the ice-cream sandwich, but nothing beats dipping a plain churro into a mug of hot chocolate. If the Centro is too much of a journey, they have a new stand at the Mercado Roma.
Chiquitito Café
Alfonso Reyes 232, Colonia Condesa
It was only a matter of time before Mexico City got its own hipster fair-trade artisanal café, and this teensy one couldn't be more on point when it comes to sustainability. As the name implies, the perfectly roasted and brewed espresso comes from a small grower in the state of Veracruz, which is famous for its coffee. Fittingly, they serve up a great café con leche, a warm and sweet milky coffee drink that's famous in that part of the country, along with cappuccinos, matcha lattes, chai teas, and more.
Ojo de Agua
Glorieta Citlaltepetl 23, Colonia Condesa
Freshly squeezed fruit juices are a regular part of everyday life in Mexico city. You can buy them by the liter at any local market, and with rare fruits like guava, pitahaya, and watermelon, the variety of combos is hard to beat. So it was only a matter of time before someone came along and made it all a bit healthier. At Ojo de Agua, they make fruit juices fresh from the ingredients in their rustic, market-like display, along with the healthier, green juice options—many with cactus leaf—ginger shots, and the like. In addition to the juices, their menu of super fresh salads and veggie sandwiches come as a nice relief from the tacos and tortas that make up most every other day's dining.
Culinary Backstreets Walking Tour
So this isn't a specialty shop at all: it's actually a website and awesome tour company that organizes several monthly food tours in the Centro Histórico (and will lead you to some of the best specialty shops and purveyors). They've done an amazing job of finding rad street food stands and old-school treasures, and creating a totally enlightening tour that doesn't feel trite or touristy in the least. It's worth booking ahead as their small expeditions fill up quickly.
Dulcería de Celaya
5 de Mayo #39, Colonia Centro
This is one of the most beautiful candy shops in Mexico, if not the world. In the same spot in the Centro for over a century, the space itself is a relic from a time past: The wooden display cabinets, baroque-style mirrors, and even the sign haven't changed in over 100 years. The sweets haven't changed much either, as the Dulceria is one of the only places where you can still find such an array of traditional sweets from cajeta, to mazapan, to cocadas, to an insanely sweet, perfectly moist pay de rompope (eggnog cake).
La Nicolasa
Clavería 235, Colonia Clavería
If you ever wondered how and where chefs like Enrique Olvera of Pujol find the rare, organic, regional ingredients that even locals don't know about, it's at this famous delicatessen in off-the-beaten-track Colonia Claveria (though there's a new-ish sister shop in Condesa now, too). Here, Chef Gerardo Vazquez Lugo, the man behind the wonderful Restaurante Nicos, and one of the main representatives for Slow Food in Mexico, sources the best regional products across the country, from Oaxacan cheeses, to foraged mushrooms, ancient grains, dried chilies, and more.
Nevería Roxy
Fernando Montes de Oca #89, Colonia Condesa
The Condesa locale of this authentic soda fountain and sorbet (nieve) shop has been around since the late 1940's, serving up light sorbets, milkshakes, and ice cream sundaes. Today it remains pretty much unchanged and totally retro, with the addition of a few well-executed replicas in other Mexico City neighborhoods. While they'll put together a mean banana split, a single scoop cone of any of their sorbets (lemon, mandarin, mamey, chicozapote, melon, pineapple, etc.) hits the spot.
Panadería Rosetta
Colima 178 A, Colonia Roma
You'll be lucky if you can grab a seat at this charming and teensy hole in the wall, but you can always take their incredible pastries and snacks to-go on a walk around the Roma. The Panadería is an extension of the acclaimed Italian restaurant Rosetta, where chef Elena Reygadas was churning out European breads and pastries of such quality, that its own separate bakery (now two) was in order. The croissants, cinnamon rolls, ricotta rolls, and focaccias are pretty perfect, and a nice break from the traditional Mexican classics.