Nassau County’s masked, knife-wielding robber struck again early Tuesday, making off with cash from a Dunkin’ Donuts in North Valley Stream, police said.

The robbery is being investigated as part of a pattern that includes at least a dozen robberies since March 1, Nassau County police said.

Nassau detectives believe the same man is responsible for hitting seven Dunkin’ Donuts shops, one 7-Eleven store, two Subway restaurants, and two Carvel ice-cream stores.

Last month, after he robbed a Subway in New Hyde Park, police called his arrest their No. 1 priority.

In the Tuesday robbery, the suspect, armed with a knife, approached the counter of the Dunkin’ Donuts at 238-19 Linden Blvd. at 12:01 a.m. and demanded an employee open the cash register, police said.

After obtaining an undisclosed amount of cash, the robber fled and was last seen on foot heading north on 238th Street, police said in a news release.

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None of the four employees was injured, police said.

The robber’s description matched that of suspects in the previous robberies; he’s about 25 years old, 6 feet tall with a medium build. He wore a dark-colored hooded jacket, bluejeans and tan work boots. He also covered his face, wearing dark sunglasses and a dark-colored cloth across his face.

The times of the robberies have been between 9 p.m. and 12:30 a.m., according to Nassau police. Suffolk police said they suspect the same man of robbing a Carvel in Commack on April 26.

Anyone with more information can call Crime Stoppers, which has in this case increased its reward offer to $10,000, at 800-244-8477. All information will be kept confidential.