GREENWICH VILLAGE A McDonald’s cashier is caught on a horrific cell phone video using a metal rod to brutally beat two female customers who’d jumped the counter of his West 3rd Street restaurant early Thursday during a fight over their order. The cashier, who police said had previously served a decade for manslaughter, beat the women so badly that one suffered a fractured skull and broken arm in the shocking attack, which was captured on a customer’s cell phone and then posted to YouTube. Police have charged the cashier, identified as Rayon McIntosh, 31, with felony assault, along with criminal possession of a weapon. Both women were charged with menacing, trespass and disorderly conduct. McIntosh is being held at the Manhattan Detention Complex on $40000 bail, according to the Department of Correction website. The drama began about 12:30 am Thursday when the two customers Denise Darbeau, 24, of Queens, and her pal, Rachel Edwards, 24, of Brooklyn entered the popular fast food spot, near Sixth Avenue, and began giving McIntosh a hard time, police sources said. The McDonald’s on West 3rd Street, near Sixth Avenue (DNAinfo/Ben Fractenberg) In the video, Darbeau is clearly heard cursing at McIntosh after another cashier told her he had to scan a $50 bill to make sure it was authentic before he would give them their food. That’s when all hell breaks loose. An agitated Darbeau is seen slapping McIntosh across the face, prompting him to lunge forward and shove the two <b>…</b>