(Rated PG-13 )   Baby got back! If the Nutty Professor and Mrs. Doubtfire collided in the form of a black Southern grandma, this would be her! Starring Martin Lawrence as our hero Big Momma, a crass Southern scale-tippin’ granny. When a dangerous convict’s bold prison break jeopardizes the safety of a young single mother (Nia Long) and her son, the FBI dispatches a top agent, Malcolm Turner (Martin Lawrence), the master of disguise, to protect them. Of course Lawrence is falling for Long (think “Tootsie” – what’s a guy to do with a girl when he’s a girl too.) Side note: Going incognito to do this role was difficult when they filmed last August in Georgia’s sweltering temperatures causing Lawrence to collapse and be hospitalized from heat exhaustion. One of the film editors was soon prepared with a cooling ventilation system built into Momma’s suit. How did he know? He was on the crew that did “Mrs. Doubtfire.” Directed by Raya Gosnell “Home Alone III”, the plot is fresh and cute (Lawrence has to find a way to get his man and his woman). Like “Blue Streak” it’s destined to be a success since the only other option is “Nutty Professor 2” later this summer. Been there, done that.