And where are you from?
I ask because two radio commercials that I’ve heard lately pronounce it with the “t.” That just sounds wrong to my ears.
I’m pretty sure most people I know pronounce it as “OFF-en.”
There’s a definite T when I say it. I’m from the Chicago area.
I’m from eastern Washington state (where the dialect is heavily influenced by California and the upper Midwest) and pronounce the T. But in voice classes in acting college, my voice teachers tried to beat it out of me.
Frequently.
Both, and I’m not sure which one I use more frequently. I voted for OFF-tin since it sounded better when I just repeated a few phrases using both pronunciations.
From southern New Jersey.
Offen. Lifelong Californian.
Offin. Central Arkansas.
I use both, but think I use “OFF-ten” more…often. From New Hampshire.
No T for me. I spent most of my life in Baltimore, Maryland.
No “t” for me. born in Birmingham, Alabama. raised in Mobile, Alabama
I voted for “off-tin”, but now I’m not sure any more… 
Off’n. Central Texas.
Both, pretty interchangeably, though I voted off-tin as that’s probably the one used most often. I’m from the Midwest (IL).
+1
Exactly where my mind went when I saw the thread title.
Offen. Lifelong resident of Northeast Texas.
Hearing the “t” always sounds wrong to my ears.
Exactly the same for me, including how I voted, except that I grew up in California and have spent the last several years in the Midwest. (Some of my diction is still strongly Californian, and some of it’s more Midwestern and I can’t tell what came from where at this point.)
Where’s the ‘other’ option?!
Of tin?? ‘tin’??
often.
I like to listen to Bach often, but I don’t like listening to Offenbach.
I’m a Brit and there’s no way I’d say “in” on the end. I’d use a schwa, but hardly any of it - “OFF-ən” but more like “OFFn”.