So how adorable is Zach Braff?

This adorable:

I'm sitting in the hallway of a swanky Boston hotel when an elevator opens and out steps the tousle-haired ``Scrubs" star, carrying a box of Dunkin' Donuts atop his fingertips as if it's a silver-domed tray.

``Want one?" he offers sweetly as he passes, lifting the cover on an especially gooey-looking assortment. I joke that I'll need to enshrine the doughnut rather than eat it, because of its brush with celebrity. ``Take two," he says helpfully, despite the fact that we haven't yet even been introduced.

Actor, writer-director, funnyman, Grammy winner, benevolent pastry guy. Is there anything Braff doesn't have going for him? The answer appears to be no, which is how he gets away with being such a heel in his new movie, ``The Last Kiss," which opened Friday.

A remake of Italian filmmaker Gabriele Muccino's 2001 hit, ``L'Ultimo Bacio," the Tony Goldwyn-directed ``Last Kiss" is a meditation on the angst of turning 30 -- the new 40 for those who want to accelerate a midlife crisis even as people are actually living longer. Braff plays Michael, an up-and-coming architect who feels trapped by impending fatherhood and the idea that he may be settling into monogamy with a smart, gorgeous woman (Jacinda Barrett) who's just perfect for him.

Yes, we should all have such problems. Still, the film's many conflicted characters (Casey Affleck, Rachel Bilson, and Blythe Danner are among the costars) and its candid examination of male-female dynamics make it a lively conversation starter, as Braff found out when we finally sat down for an interview in a hotel meeting room some minutes after those doughnuts had been digested.

The actor entered the room just as several women were dissecting the choices and behaviors presented in ``The Last Kiss" screenplay by Paul Haggis, who also penned ``Crash" and ``Million Dollar Baby." Is the new movie realistic about infidelity and forgiveness, some of us wondered? Are the female characters too demanding, the male characters too immature, and all of them too needy? Did Haggis and Goldwyn get it right in the end, taking an approach that is both more ambiguous and more honest than the Italian original?

Braff thinks that Michael's pivotal moment, when he chooses between being fully accountable for an indiscretion or hiding behind a half-truth, is the thing that saves both the character and the film.

``You can't be fully in [a relationship] if there's baggage," Braff says. ``Even at the cost of losing the love of his life, [Michael] chooses his integrity, and I think that's what buys the character back."

But isn't there always baggage in a relationship?

``There's always baggage. But there's large baggage and then there's carry-ons," the performer quips. Braff's breakout film, ``Garden State," was about the large baggage.

In that impressive, semiautobiographical 2004 work, which marked the New Jersey native's feature debut as a writer-director, Braff played a confused, over-medicated actor derailed by a family tragedy. It was a quieter portrait, but not unrelated to his current role and most others on his resume. Braff's forte is playing funny-cute guys who are stunted and flawed but somehow heroic, from J.D. on ``Scrubs" right down to a cartoon Chicken Little.

``That's a delicate line, and it requires a very skillful performance," says ``Last Kiss" director Goldwyn, in town for a recent Boston Film Festival screening of the movie. He equates Braff's rare combination of comic-dramatic chops, bumbling intelligence, and regular-guy-except-when-I'm-a-movie-star charisma to that of Tom Hanks.

``With the wrong actor [playing Michael], if you didn't care about him, the movie would fall apart," Goldwyn explains. ``Zach is the only one I would have wanted to cast in this part. It was the thing that gave me great ease going into the project. . . . He feels like someone you know, as opposed to some idealized version of a man."

Also like most Braff characters, Michael is at an important crossroads for embracing change and growth. At 31, Braff can relate. His romantic relationship with singer-actress Mandy Moore ended a few months ago, and as he runs out the contractual clock on what is probably his final season of ``Scrubs," questions abound about what he'll focus on next.

``I think I'll be very sad [when I'm done with the series]," the star admits, without offering any timetable or inside information. ``But I think when it's time to go, I'll know. There's something very classy about going out on top."

And on top is undeniably where he's currently sitting, with an enviable pile of options.

After handpicking the Grammy-winning ``Garden State" soundtrack, he was asked to do the same for ``The Last Kiss," which features tracks by Snow Patrol and Joshua Radin. He thinks about spending more time on his hobby, photography. And he hopes to see filming of ``Andrew Henry's Meadow," a Doris Burn children's book he adapted with his brother Adam. (Another brother, Joshua, wrote the novel ``The Unthinkable Thoughts of Jacob Green.")

``I feel very creatively challenged right now," the most famous Braff acknowledges. ``I don't feel at all limited."

So if, after six seasons, he says goodbye this year to the most inspired over-the-top comedy on television, there's a silver lining for ``Scrubs" fans. Whether or not the much-rescheduled and dysfunctionally parented show continues without him, Braff says he'll be more inclined to leap at broadly comedic movie scripts when he's not doing weekly pratfalls in your living room.

In fact, he appears to have begun that transition even now. His next film is ``Fast Track," a zany romantic comedy directed by former Lemonheads bass player Jesse Peretz, in which Braff plays an underachiever who reluctantly goes to work for his father-in-law (Charles Grodin). He may also follow in Chevy Chase's footsteps to star in ``Fletch Won," under the direction of ``Scrubs" creator Bill Lawrence, though the actor says there's no deal in place for that yet.

But he'll also still do the kind of movies he personally prefers to watch, ``movies that are thought-provoking and inspire conversation," as he puts it. Sometime next summer Braff hopes to direct and costar in his second feature, ``Open Hearts," a remake of Danish director Susanne Bier's dark drama about two couples thrown together by a devastating car accident.

That doesn't sound like a guy who's afraid of embracing change. It sounds like a 31-year-old who's just getting started.

Janice Page can be reached at jpage@globe.com.