Pulse first 3 ingredients in a food processor 3 or 4 times or just until blended. Add butter, and pulse 5 or 6 times or until crumbly. Whisk together egg yolks and 1 Tbsp. ice-cold water in a small bowl; add to butter mixture, and process until dough forms a ball and pulls away from sides of bowl, adding up to 1 Tbsp. remaining ice-cold water, 1 tsp. at a time, if necessary. Shape dough into a disk; wrap in plastic wrap. Chill 4 to 24 hours.

Roll dough into a 14-inch circle on a lightly floured surface. Fit dough into a lightly greased 9-inch dark springform pan, gently pressing on bottom and up sides of pan; trim and discard excess dough. Chill 30 minutes.

Meanwhile, preheat oven to 325°. Beat cream cheese at medium speed with an electric mixer 3 minutes or until smooth. Gradually add granulated sugar, beating until blended. Add eggs, 1 at a time, beating just until yellow disappears after each addition. Beat in vanilla.

Pour two-thirds of cheesecake batter (about 4 cups) into prepared crust; dollop 1 cup lemon curd over batter in pan, and gently swirl with a knife. Spoon remaining batter into pan.

Bake at 325° for 1 hour to 1 hour and 10 minutes or just until center is set. Turn oven off. Let cheesecake stand in oven, with door closed, 15 minutes. Remove cheesecake from oven, and gently run a knife around outer edge of cheesecake to loosen from sides of pan. (Do not remove sides of pan.) Cool completely in pan on a wire rack (about 1 hour). Cover and chill 8 to 24 hours.

Remove sides of pan, and transfer cheesecake to a serving platter. Spoon remaining 1 cup lemon curd over cheesecake, and, if desired, top with Candied Lemon Slices.

Candied Lemon Slices:

Cut lemons into 1/8-inch-thick rounds; discard seeds. Stir together sugar, lemon juice, and water in a large skillet over medium heat until sugar is dissolved. Add lemon slices, and simmer gently, keeping slices in a single layer and turning occasionally, 14 to 16 minutes or until slightly translucent and rinds are softened. Remove from heat. Place slices in a single layer in a wax paper-lined jelly-roll pan, using tongs. Cool completely (about 1 hour). Cover and chill 2 hours to 2 days. Reserve syrup for another use.