The suspect strolled into a Dunkin' Donuts at 132 Nassau St. around 4:15 a.m. and asked a 22-year-old man behind the counter for a doughnut, sources said.
When the worker rang up the purchase, the robber stuck his hand in the till and grabbed a fistful of cash, police sources said.
Once he had his fill of dough, the suspect ran outside and swiped a nearby bike and pedaled away, sources said.