What in the world is a Tarte Tatin? In the world of France it is a famous upside-down apple tart.  This dessert was created by two French sisters who lived in the Loire Valley and earned their living making it. This  The French call this dessert tarte des demoiselles Tatin, “the tart of two unmarried women named Tatin.” Information is found in FOOD LOVERS COMPANION, pp686-7
les light corn syrup

Though traditionally made with apples, the tart can be made with any fresh fruit. The first time I made it I used pears with my own handmade crust and cooked it in an iron skillet. The next time I used both apples and pears with a Pillsbury crust and cooked it in my new tarte Tatin pan from Le Creuset. I have found two recipes that look better than either of the ones I have made, and I plan to make one of them on Thursday of this week–all things being equal!

TARTE TATIN (from Gourmet, March 2001)
Serves 8
Active time: 30 minutes
Start to finish: 1 1/4 hr
Ingredients

frozen puff pastry sheet (from a 17 1/4-ounce package)
1/2 stick (1/4 cup) unsalted butter, softened
1/2 cup sugar
7 to 9 Gala apples (3 to 4 pounds), peeled, quartered lengthwise, and cored
Special equipment: a well-seasoned 10-inch cast-iron skillet
Instructions
Preheat oven to 425°F.Roll pastry sheet into a 101/2-inch square on a floured work surface with a floured rolling pin. Brush off excess flour and cut out a 10-inch round with a sharp knife, using a plate as a guide. Transfer round to a baking sheet and chill.
Spread butter thickly on bottom and side of skillet and pour sugar evenly over bottom. Arrange as many apples as will fit vertically on sugar, packing them tightly in concentric circles. Apples will stick up above rim of skillet.
Cook apples over moderately high heat, undisturbed, until juices are deep golden and bubbling, 18 to 25 minutes. (Don’t worry if juices color unevenly.)
Put skillet in middle of oven over a piece of foil to catch any drips. Bake 20 minutes (apples will settle slightly), then remove from oven and lay pastry round over apples.
Bake tart until pastry is browned, 20 to 25 minutes. Transfer skillet to a rack and cool at least 10 minutes.
Just before serving, invert a platter with lip over skillet and, using potholders to hold skillet and plate tightly together, invert tart onto platter. Replace any apples that stick to skillet. (Don’t worry if there are black spots; they won’t affect the flavor of the tart.) Brush any excess caramel from skillet over apples. Serve immediately.
Cooks’ note:·Tart can cool in skillet up to 30 minutes. It can also stand, uncovered, up to 5 hours, then be heated over moderately low heat 1 to 2 minutes to loosen caramel. Shake skillet gently to loosen tart before inverting.


II am including the following recipe from Bon Appetit just to give a different method


ROASTED PEAR TART TATIN (from Bon Appetit, December, 2008)
Ingredients
1/2 cup sugar
1/4 cup unsalted, cut into small cubes
2 tablespoons corn syrup
4 large Bosc pears (2 1/4 to 21/2 lbs), peeled, halved and cored
1 sheet frozen puff pastry (half of a 17.3 oz package), thawed
1 1/2 tablespoons pear nectar
Instructions
Position 1 rack in center and 1 rack in top third of oven and preheat to 375°F. Sprinkle sugar evenly over bottom of heavy 9-inch diameter cake pan with 2-inch-high sides.Scatter butter cubes over sugar, then drizzle with light corn syrup. Arrange pear halves, cut side up and narrow end pointing toward center, snugly in cake pan (pears may not lie flat, but will shrink during cooking and fit evenly).
Place pan on center rack in oven. Bake pears until tender and dark brown in spots, about 2 3/4 hours.
Meanwhile, line large baking sheet with parchment paper. Unfold thawed puff pastry sheet on work surface. Using another 9-inch-diameter cake pan as guide, cut 9-inch round from pastry sheet. Place pastry round on prepared baking sheet. Place baking sheet on upper rack in oven and bake pastry round until puffed and golden brown, about 20 minutes. Cool pastry round completely.
Using slotted spoon, carefully lift pears from syrup in cake pan and transfer to large plate to cool. do ahead Pears and pastry round can be made 4 hours ahead. Reserve cake pan with syrup. Let pears, pastry, and syrup stand at room temperature. Before serving, place pastry round, flat side up, on platter. Carefully arrange pears, cut side down and narrow end in center, atop pastry round. Place pan with syrup over medium-high heat. Boil until syrup turns dark amber color, whisking occasionally, 2 to 3 minutes. Remove from heat. Add pear nectar (mixture will bubble up). Whisk until caramel is smooth, then spoon over pears.