Cafe Giang is down a narrow alley off Nguyen Huu Huan Street in the Old Quarter — easy to miss if you don't know to look for it. Inside, the small rooms have the accumulated patina of a family business that has been in continuous operation for eighty years: dark wood furniture, old photographs, the smell of coffee and sweet egg. The egg coffee (ca phe trung) is the reason to come: a small cup of strong Vietnamese robusta espresso, topped with a thick, warm, slightly custardy foam of beaten egg yolk and condensed milk. It tastes more like coffee-flavored dessert than coffee, which is not a criticism.
Drink it as intended: use a small spoon to fold a little of the foam down into the coffee with each sip, working through the layers. The hot version is served in a cup nested inside a bowl of warm water to keep it at temperature. There is also an iced version, and a coconut coffee. The cafe is always busy, particularly on weekends; you may need to wait for a table. The family has opened additional branches around Hanoi, but this original location on the alley is the right place to come.