You write just like everyone normally writes, by dropping the accent. I only see such spellings when people are trying to convey some sort of sophistication, rather than in casual, day-to-day use.
We have café all the way from McDonalds up to Buckingham Palace.
McCafe and Buckingham Palace would want the "sophistication angle". Both spellings work obviously, but IMO (and the majority of English books) "cafe" is the "correct" spelling.
https://books.google.com/ngrams/graph?content=caf%C3%A9%2Cca...
If a Chinese person adopts an English name, they'll put it first, however. Eg "Jake Ma".
Variants: cafe