Directions

For caramel sauce:
Bring sugar, cream, and butter to boil in heavy medium saucepan over medium-high heat, whisking constantly until sugar dissolves. Boil until caramel thickens enough to coat spoon thickly, whisking often, about 10 minutes. DO AHEAD Caramel sauce can be made 5 days ahead. Cover; chill. Whisk over low heat until warm before using.
For crust:
Blend flour, powdered sugar, and salt in processor. Add butter and blend until coarse meal forms. Add egg yolks. Pulse until moist clumps form. Gather dough into ball; flatten into disk. Wrap and chill at least 1 hour. DO AHEAD Dough for tart crust can be made 1 day ahead. Keep chilled.
For filling:
Whisk first 4 ingredients in large bowl to blend. Add apples and toss until evenly coated.
Preheat oven to 375°F. Roll out dough on lightly floured surface to 13-inch round. Transfer to 9-inch-diameter tart pan with removable bottom. Cut overhang even with top of pan sides. Press sides of dough to bring 1/4 inch above sides of pan. Arrange apple quarters, cut side down, in circle around outer edge of pan, fitting snugly. Cut remaining apple quarters lengthwise in half; stand in center of tart, fitting snugly.
Bake tart until apples are tender, about 1 hour 15 minutes. Remove tart from oven; brush with some of caramel sauce. Cool tart to room temperature. Rewarm remaining caramel sauce. Drizzle tart lightly with sauce. Serve, passing remaining sauce separately.