Amanda Bynes has been making the most of the sunny L.A. winter lately ... stepping out for a smoke break and getting a little cozy with her boo, Zachary!

Check the pics from Tuesday ... the former child star matched with Zachary as the two cozied up outside, with him posted up close and a hand resting on her lower back while they sat in the shade.

Judging by the fits, it was very much a laid-back day -- Amanda rocked an oversized Interstate nylon coach jacket and UGG boots while running errands with her man.

Amanda's been out and about a lot lately ... showing off her 28-pound weight loss after using Ozempic.

Looking good, Amanda -- and it’s pretty clear Zachary agrees!