Hanoi is a city for coffee lovers – there is barely a street in the capital without a café. You can get coffee at any time of the day or night, and it is usually strong, rich and with a typical nutty taste that resembles Vietnamese coffee for me.
There is no Starbucks or similar foreign coffee chain in Hanoi, but what I found even more enjoyable is Cộng Càphê, which is a local chain with about 5-6 outlets (I managed to visit four of them, one close to the West Lake, the other one next to the Cathedral, one is in the vicinty of the Opera and then another one in the Old Quarter).
Cộng Càphês are unique in their style, they look like a coffee shop in the olden days might have looked like. The colours are all green and brown, the menus are scrawled on hardback works by Lenin, drinks are served in retro enamel cups and old propaganda posters adorn the walls.
Most of them have outdoor seating space, so you can sit outside, drink nau da (iced white), den nong (hot black), suaa chua (with yogurt) or cot dua (with frozen coconut) coffee. I recommend you try the cot dua – it is strong and sweet and highly addictive!
bluebalu 
I love anything with coconut. So looking forward to trying this out :-)