How do you pronounce "marshmallow"?

I pronounce it "marsh mellow".

Me too.

I say "Marschmelloh"

Just like Mallows that grow near Marshes.

marsh mellow

marshmellow /ˈmɑɹʃˌmɛl.oʊ/

In Wicklow, "marsh-malluh"
In Antrim, "mersh-mawlleh"
In Texas, "mursh-meller"
In Virginia, "mawsh-meylleu"

You say eether and I say eyether,
You say neether and I say nyther;
Eether, eyether, neether, nyther,
Let's call the whole thing off!
You like potayto and I like potahto,
You like tomayto and I like tomahto;
Potayto, potahto, tomayto, tomahto!
Let's call the whole thing off!

I sometimes forget it's spelt with an 'a' so tend to pronounce it 'marshmellow' too, but if I'm conscious of it's spelling I'll say MarshmAllow. I'm Aussie.

You base your pronunciation on spelling? Then why don't you pronounce R's as they're spelled? LOL

Like marsh-mellow. I'm from Texas, definitely not "marsh-meller." lol

Perhaps not where you are, Skippy - but there is more than one Texas accent, East, West, Central, Gulf &c. &c.

So some fellers'll holler fer a marshmeller !

http://www.pbs.org/speak/seatosea/americanvarieties/texan/drawl/

Do you speak American? Damn if I liked those videos!