Forget “Jack and Jill” and the fact that Adam Sandler plays them both and not particularly well in his new “twins” comedy. Al and Pacino almost reason enough to see it, all by his bigger-than-life self.

Can I get a “HOO hah?”

Pacino plays a scary, cartoonish and more over-the-top-than-usual version of himself in this farce  and scores big laughs with every entrance. He’s performing Richard III on the L.A. stage, bellowing at cell phone users. He may take “Man of La Mancha” to Broadway, even though he sings like Sinatra’s pet bullfrog.

And he’s mad for Jill, Jack’s obnoxious Bronx cheer of a sister, whom he met while sitting next to Johnny Depp (in a Justin Bieber t-shirt) at an L.A. Lakers game.

Jack (Sandler) is a wealthy TV commercial director who can’t stand his yenta-sibling, Jill (Sandler again). She comes to visit over the holidays, craving a little “twin time,” and all Jack can think of is ditching her.

“We shared our mother’s WOMB,” Jill pleads. “We’re WOMB-mates!

Jack needs Pacino to do this new “Dunkaccino” commercial for Dunkin Donuts, so when Jill catches the wild-eyed Oscar-winner’s attention, Jack needs his twin, or her clothes in case he has to dress up like her to “close the deal.”

Even by sloppy Sandler movie standards, this one’s a wreck — fart jokes, potty zingers and pit-stain gags. Cameos from info-mercial stars and ex-”Saturday Night Live” colleagues litter the set, along with product placement from a certain pink stomach medicine, the aforementioned donuts and even a cruise line.  Mexican comic Eugenio Derbez does some catchphrase shtick.

A running gag that works — scripted and funny “interviews” with real twins open and close the film and are funnier than anything Sandler’s house director, Dennis Dugan, has ever managed. They’re the reason “Jack and Jill” starts off as though its going to be far more evolved than the usual lowbrow how-low-can-they-go wallow.

Sandler’s such a feeble actor that his bellowing rages never match the expression he musters on his blank face. He puts all his efforts into playing a woman, broadly and badly, so much so that the male twin is even duller than standard-issue Sandler.

But then there’s Pacino, out-of-place and yet somehow right at home. You want big? Al does BIG.  And since is as close as we’re likely to get to “Don Corleone Does Don Quixote,”  that alone is worth the price of admission.

MPAA Rating: PG for crude and sexual humor, language, comic violence and brief smoking

Cast: Adam Sandler, Katie Holmes, Al Pacino, David Spade

Credits:  Directed by Dennis Dugan, written by Steven Koren and Ben Zook. A Sony/Columbia Pictures release. Running time: 1: 34