Chevre Cheesecake

Make Cheesecake: Put oven rack in middle position and preheat over to 325 degrees F.

Wrap outside of springform pan with a large sheet of heavy-duty foil to waterproof it. Butter pan and line bottom with a round of parchment, then butter parchment. Dust pan with sugar, gently knocking out excess.

Boil cream with 3/4 cup sugar in a 1- to 1 1/2-quart heavy saucepan over moderately high heat, uncovered, stirring occasionally, until reduced to about 1 1/4 cups, about 8 minutes.

Transfer cream to a metal bowl and set bowl in a larger bowl of ice water, then cool to room temperature, stirring occasionally.

Halve vanilla bean lengthwise and scrape seeds into a large bowl. Add goat cheese and cream cheese, then beat with an electric mixer at medium speed until fluffy, about 2 minutes. Reduce speed to low and add cream in 3 batches, mixing well after each addition. Add eggs 1 at a time, mixing well after each.

Pour batter into springform pan and put in a roasting pan, then pour 1 inch lukewarm water into roasting pan. Bake until cake appears set but still trembles slightly in center when gently shaken, about 1 hour. (Cheesecake will rise slightly in oven, then fall slightly.)

Run a knife around edge of cake to loosen it, then cool completely in springform pan on a rack (cake will continue to set as it cools). Chill cake in pan loosely covered, 8 hours.

Make Spiced Poached Pears: Cut a round of parchment large enough to just fit inside a 2- to 3- quart heavy saucepan. Set parchment round aside.

Stir together Port, sugar, water, zests, lemon juice, spices, and vanilla bean in saucepan and bring to a boil.

Meanwhile peel, quarter, and core pears, then add to Port mixture and cover surface directly with parchment round (pears may poke through liquid).

Poach pears at a bare simmer until tender when pierced with a knife, 25 to 30 minutes.

Remove from heat and cool pears in liquid, covered with parchment, about 1 1/2 hours. Transfer pears and poaching liquid to a bowl and chill, covered, at least 8 hours.

Make Shortbread Crust: Line a baking sheet with parchment. Beat together butter, vanilla, and salt in a large bowl with cleaned beaters at medium speed until fluffy, about 2 minutes, then beat in brown sugar. Reduce speed to low and add flour, mixing until just incorporated.

Transfer dough to baking sheet and shape into a disk. Cover with plastic wrap and roll out into an 11-inch round (about 1/8 inch thick) directly on parchment, then chill on baking sheet at least 4 hours.

Put oven rack in middle position and preheat oven to 350 degrees F. Remove plastic wrap from dough, and, using bottom of springform pan as your guide, cut out a 9-inch round of dough, removing scraps. Bake shortbread until edge is golden brown, 10 to 15 minutes. Cool completely on baking sheet on a rack.

Make Port Reduction: Gently transfer pears to a paper-towel-lined plate with a slotted spoon, then pour poaching liquid through a fine-mesh sieve into a measuring cup (you should have about 1 1/3-cups), discarding solids.

Return liquid to saucepan and boil, uncovered, over high heat, until slightly thickened and reduced to a scant cup, about 8 minutes. Cool to room temperature.

Assemble Cake (just before serving): Blot any condensation from top of cake with paper towels if necessary. Remove side of pan and run a large knife along bottom of pan (under parchment) to loosen parchment from bottom, leaving pan in place.

Cover top of cake with a clean sheet of parchment, then invert a baking sheet directly over parchment and invert cake onto sheet. Remove pan, then peel off parchment from cake.

Invert shortbread onto cake, then carefully invert a serving plate over shortbread. Holding baking sheet and serving plate together (with cake sandwiched in between), invert cake onto serving plate (shortbread will be underneath cheesecake) and peel off parchment from top of cake.

Cut pears into 1/4-inch-thick slices and arrange evenly on top of cake. Serve slices of cake with Port reduction on the side.