A Bronx McDonald’s worker was arrested this week for allegedly selling cocaine and crack cocaine along with the burgers and fries normally on offer at the fast-food giant.

Frank Guerrero, the night shift manager at a 24-hour McDonald’s on Bruckner Boulevard, was accused by prosecutors of slipping the drugs into the company’s signature paper bags.

Guerrero, 26, was arrested after a three-month investigation — “Operation Off the Menu” — in which he allegedly sold to an undercover officer.

Guerrero was charged on Wednesday with criminal sale of a controlled substance, criminal possession of a controlled substance, criminally using drug paraphernalia and unlawfully dealing with a child, according to ICE Homeland Security investigators and the city’s Office of the Special Narcotics Prosecutor.

He was arrested inside the McDonald’s where he worked in the Soundview section of the Bronx.

Guerrero would allegedly unlock the front door to the restaurant for the drug sales (only the drive-through window is open at night). Other employees were working in the restaurant at the time, according to prosecutors.

He is accused of making eight sales to an undercover officer to the tune of nearly $10,900.

In one instance, he put cocaine inside a cookie bag, which he then put inside a larger McDonald’s order of two cheeseburgers, a soda and fries, according to prosecutors. And on Sept. 22, prosecutors said he sold 100 grams of cocaine and some crack cocaine — first retrieving them from a restroom soap dispenser he used to hide the drugs — to an officer for more than $6,500.

When police arrested Guerrero, they said they found plastic bags on a shelf in the back of the restaurant, as well as 200 grams of cocaine and about $5,300 in cash inside a dresser in a toddler’s play room at his Pelham home.

The child’s mother, Leidy Cabral Castillo, 24, was also charged with criminal possession of a controlled substance, criminally using drug paraphernalia and unlawfully dealing with a child, according to prosecutors.

Guerrero was held on $750,000 bail during his arraignment Wednesday night. Cabral Castillo was released without bail during her arraignment on Thursday.