Paul Reubens -- Pee-Wee Is Back ... La La La La La La La!

Hooorayyyyy!!!! The red bow tie rides again ... Pee-Wee Herman is out in L.A. gearing up for a new big adventure ... for the first time in a long time.

"Pee Wee's Big Holiday" is being produced by Judd Apatow for Netflix ... and Paul Reubens was shooting Tuesday, and the guy looks like he hasn't aged a freakin' day.

Don't hold your breath if you're hoping to catch up with Dottie or Large Marge -- it's been reported the new movie will have brand new characters. Bummer, Chairry.

Jambi better get on the phone to his agent, stat.