Oh, the pull of that elusive reservation at the hot new restaurant. And double-oh the sweet and fatty decadence of a well-made dessert. Combine the two foodie emotions and you’ve got the Cronut.

There’s a frenzy going on — Manhattan style — for the croissant-doughnut hybrid that went on sale in limited quantities several weeks ago at the tiny downtown shop of French chef Dominique Ansel.

Cronut lusters began lining up almost from the start after word spread on blogs. They’re now 100 strong most mornings for the chance to nab the quirky, fried treats, including some who show up at 6 a.m., two hours before the door opens at the Dominique Ansel Bakery in SoHo.

Some often leave empty handed, or at least Cronut-less if they turn up their noses at the 30 or so other items on Ansel’s menu. He makes only 200 to 250 Cronuts every morning (it takes three days to complete the process) and has been selling out within an hour. He limited his customers to two per person at the cash register one recent day. That’s down from three.

“A little bite of heaven. Definitely worth the calories,” said Kyra Parkhurst, in town from Park City, Utah, after arriving about 7:30 a.m. and cajoling Ansel to sign her gold, cardboard carry box once she made it inside.

For those who don’t make it inside, more than a dozen people who have scored already-trademarked Cronuts have been scalping them online for up to $40. That’s eight times Ansel’s asking price of $5 a piece and can include delivery to as far away as Queens and Brooklyn.

Ansel is taking pre-orders two weeks out, allowing for six per customer that way. He’s also taking reservations for orders of 100 or more months in advance.

“We try to make enough for everybody,” said the soft-spoken chef who worked for seven years under the exacting heavy hitter Daniel Boulud before opening his own bakery a year and a half ago.

So what’s the big deal, and exactly what is the calorie count? Ansel, 35, isn’t giving up his recipe. Copycats have already started to mimic his creation. The answer to the latter question isn’t great news for most of us, though the chef was tightlipped.

“I’m not sure how many calories, but it’s very tasty,” Ansel smiled. “I wanted to do something new and original. I wanted to do something fun to eat.”

He acknowledges loads of butter, along with cream injected through multiple layers with a syringe-like pastry tip and a glaze on top that encircles the hole in the middle. He fries each Cronut in grapeseed oil for 30 seconds, using just one pot that can hold up to nine at a time. The oil leaves outer layers crunchy, inner bites doughy.

Oh, and he rolls the sides in sugar.

Niko Triantafillou, a blogger who specializes in desserts, called the Cronut Manhattan’s answer to deep fried ice cream, but in a good, chef-y sort of way.

Ansel said it took him about two months to perfect the recipe so the tweaked croissant dough can withstand the trip through hot oil.

So what does anti-obesity campaigner Mayor Michael Bloomberg think? Ansel said we may find out: “His office has placed an order.”