Jonathan Taylor Thomas -- HEARTTHROB SURFACES ... Uses Hunky Mouth to Speak Words

O.M.G. ... It's J.T.T. in L.A. ... AHHHHHHH!!!!!!!!!!

14 years after "Home Improvement" went off the air, TMZ spotted the elusive Jonathan Taylor Thomas at the Arclight movie theater in Hollywood ... as dreamboaty as ever.

Despite being mesmerized by his sparkling blue eyes ... we managed to compose ourselves for just enough time to fire off some questions about the "Lion King." Ugh, we're soooo stupid.

Of course, the hunky 31-year-old ... who once graced every single teen magazine from "Tiger Beat" to "16" to "J-14" to "Bop" ... answered our dumb questions and even cracked that adorbs smile.

He's so much hotter than Devon Sawa!!