We got the legendary songwriter Thursday at Pink's Hot Dogs on La Brea -- where Diane was being honored with her own veggie hot dog -- and our photog asked her about that elusive Oscar's win.

Diane's nominated for an Academy Award for the 15th time in her career -- this time she's up for Best Original Song for "The Fire Inside” from the film "Flamin' Hot" -- and she told us she's just happy to be nominated and already feels like a winner.

While Diane played it cool, her partners on the film go to bat for her ... telling us she deserves to finally win an Oscar.

Becky G sings Diane's song from the Hot Cheetos movie ... and she's gonna perform it at the Oscars, along with the other nominees.

The competition includes a couple songs from "Barbie" ... the Ryan Gosling-performed song "I'm Just Ken" and Billie Eilish and Finneas' "What Was I Made For?"

Diane's movie partners, Richard and Judy Montanez, take a couple playful shots at the "Barbie" duo here ... telling us Diane's tune is way better than the Ken song.

Don't even get them started on Billie's track, which they quietly say is "depressing." No hate here, just good fun ... Billie says she was depressed when writing the song anyway.

Win or lose next weekend at the Oscars, Diane's already got another notch on her belt ... in the form of her very own Pink's hot dog.

Diane's special dog is a veggie dog topped with jalapeño pepper jack cheese, guacamole, and Flamin' Hot Cheetos.