UPPER EAST SIDE — A food fight threatens to engulf an entire neighborhood — and it will be fought with donut-bacon hamburgers and "hipster" hot dogs.
That's because two new hamburger restaurants are stepping in to offer what they say other fast food-inspired eateries — including area stalwart Shake Shack — don't.
The first player in this bun-wrapped battle royale is The Burger Bistro Three, recently opened on 1663 1st Ave., at 86th Street, by Morton's alums John Agnello and Vincent Dardanello.
The 30-seat, full-service restaurant — the third location of this Bay Ridge-based chainlet — specializes in burger customization, and also offers beer, wine and sangria.
Specials include a glazed-donut burger, which boasts bacon, American cheese and a fried egg.
A plain beef burger costs $8, but some menu items will be more expensive than at the outer-borough stores, Agnello said.
Cheese and toppings, for example, will cost 50 cents more. And several appetizers — such as nachos and a fried artichoke platter — will cost $1 more, putting them at $7 and $8, respectively.
But why open their first Manhattan location nearish Shake Shack, located at 154 East 86th St., at Lexington Avenue?
"Honestly, we don't really believe that they're competition," said Agnello, 45. "I suppose that anybody who sells a burger could be conceived as competition, but we're incredibly different in what we do."
That doesn't seem to be the case with BurgerFi, a South Florida-based company that plans on directly taking on the restaurant with patties and pups.
Steve Lieber, BurgerFi spokesman, said the company studied similar concepts — such as Smash Burger, Elevation Burger, 5 Napkin Burger, Five Guys Burgers and Fries, and Shake Shack — before launching.
"We picked and choose the best things from each program and put it together," Lieber said.
How that plays into culinary conflict: Lieber insists that BurgerFi's program offers customers more choices at slightly cheaper prices.
A single beef hamburger, Lieber said, will sell for $4.47.
Shake Shack's costs $4.55.
BurgerFi also has specialty sausages — "hipster hot dogs" — on the menu.
Available in Chicago-style "Vienna," Wagyu and chicken apple meats, they are based upon the build-your-own topping-selection concept.
BurgerFi, which just inked the lease, hopes to open by next year, Lieber said.