Where does "otay" come from?

"Otay" comes from The Little Rascals (a.k.a. "Our Gang"), a 1920's comedy series featuring a variety of child actors, in particular one called Buckwheat, who had a bit of a lisp or perhaps a minor speaking impediment at the time. This character was later caricatured by Eddie Murphy on Saturday Night Live, who made a big production out of the practically unintelligible "Buckwheat dialect", including "Oh-Tay!" specifically as a catchphrase.

When I use it, I'm deliberately emulating baby talk. It doesn't really mean anything different than "okay" (pronounced properly); it's just a way to be, I dunno, cutesy.

I didn't know about the Little Rascals/Buckwheat connection, possibly because I grew up without a TV. I'm sure Buckwheat contributed to at least some of the popularity of "otay", and possibly I absorbed it from someone who (unbeknownst to me) was imitating the TV show, but it's also possible that this is something that each generation/school/user invents anew.

I believe it comes from the character of Buckwheat in the old TV show The Little Rascals.

It absolutely originated from Buckwheat and his lisp. My entire generation grew up imitating it. I asked my 22 year old and her generation uses it from Eddie Murphy's reincarnation of Buckwheat in a movie, on record, and a reoccurring role of the character on Saturday Night Live. Then moving ahead to my 11-year-old son's generation, he sees it on Facebook, also in depictions of Buckwheat and he and his friends use it in imitating the Little Rascals.