Ca phe trung is Hanoi's egg coffee: thick, custard-like cream of whisked egg yolk and condensed milk floated on hot Vietnamese coffee, drunk like a tiramisu in a cup at Cafe Giang's alley counter.
Where to eat it: 5 restaurants across 2 cities.
Egg coffee was invented at Cafe Giang in 1946 by Nguyen Van Giang, who worked as a bartender at the Metropole Hotel. Milk was scarce during the war years, so he whipped egg yolk with sugar as a substitute. After Mr Giang passed away in 1987, his children took over Cafe Giang at 39 Nguyen Huu Huan. His daughter Mrs Bich opened Cafe Dinh on Dinh Tien Hoang in 1987 with the same recipe.
Common allergens: Egg, Dairy
Tip from the editors. Use the freshest egg you can find. The egg cap should hold its shape; if it sinks, whisk longer next time. Serve in a hot-water bain-marie to keep warm.
Café Giảng in Hanoi is where egg coffee was invented in 1946, served down a narrow alley off Nguyen Huu Huan in the Old Quarter by the founder's descendants.
Signature drink: Cà phê trứng egg coffee
Order: Ca phe trung: whipped egg yolk and condensed milk on Vietnamese coffee, the original recipe from 1946.
Tip: Down a narrow alley off Nguyen Huu Huan; the cafe is at the back of a small courtyard. Egg coffee 35,000 VND.
Why locals love it: Up an old staircase above a Hoan Kiem-side travel agency, this 1987 cafe opened by Cafe Giang's daughter Mrs Bich still serves the original 1946 egg coffee.
Tip: Six seats on the narrow balcony overlooking the lake; arrive before 09:00 to claim one.
Why locals love it: Enter through a silk shop, walk a long corridor, cross a birdcage courtyard, climb a home staircase, and arrive on a rooftop balcony with the best lake view.
Tip: Look for the red-fronted silk shop on Hang Gai marked 'Silklike'. Egg coffee 50,000 VND.
Why locals love it: A 1930s French villa second-floor cafe reached past a family shrine, with geometric tile floors, olive shutters and a soundtrack of French ballads.
Tip: The window-table for two on the second floor is the seat to ask for. Cinnamon egg coffee is the signature.
Runam is a lavish multi-storey cafe in a French-style mansion facing the cathedral, pouring Vietnamese egg coffee and hot drip alongside a full breakfast.
Signature drink: Egg coffee
Order: Egg coffee, Saigon style, with a banh mi to follow.
Tip: It faces Notre Dame Cathedral; the upstairs rooms are quieter for a slow breakfast.
More cities are in research. Want ca phe trung covered somewhere specific? Tell us where you want to eat.