Triple Citrus Cheesecake

Serves 12 to 16.   Published May 1, 2003 Cook's Illustrated

Cooks's Illustrated is the very best source for recipes if you want to know why the recipe works!

The cheesecake is baked in a bain marie, or hot water bath. To prevent water from leaking into the cake during baking, the springform pan is wrapped in a double layer of foil. To contain the water bath it's best to use a roasting pan that is just slightly larger than the springform pan so that you need not use an excessive amount of water. You will need lemon juice for both the cheesecake and the curd; it's more efficient to juice the entire amount at once. Though start to finish this recipe takes several hours, the actual preparation is simple, and baking and cooking proceed practically unattended. The cheesecake can be made up to a day in advance; leftovers can be refrigerated for up to 4 days, though crust will become soggy.

Cookie-Crumb Crust
5	ounces Nabisco Barnum's Animal Crackers or Social Tea Biscuits
3	tablespoons granulated sugar
4	tablespoons unsalted butter , melted and kept warm
Filling
1	teaspoon grated lemon zest , plus 1 tablespoon juice from 1 lemon
1	teaspoon grated lime zest , plus 1 tablespoon juice from 1 lime
1	teaspoon grated orange zest , plus 2 tablespoons juice from 1 orange
11/4	cups granulated sugar (8 3/4 ounces)
11/2	pounds cream cheese , (three 8-ounce packages), cut into rough 1-inch chunks and left to stand at room temperature 30 to 45 minutes
4	large eggs , room temperature
2	teaspoons vanilla extract
1/4	teaspoon table salt
1/2	cup heavy cream
Lemon Curd
2	tablespoon lemon juice , from one lemon
2	tablespoons lime juice , from 1 to 2 limes
2	teaspoons grated orange zest , plus 4 teaspoons juice from 1 orange
2	large eggs
1	large egg yolk
1/2	cup granulated sugar (3 1/2 ounces)
2	tablespoons unsalted butter , cut into 1/2-inch cubes and chilled
1	tablespoon heavy cream
	pinch table salt

Instructions

1. FOR THE CRUST: Adjust oven rack to lower-middle position and heat oven to 325 degrees. In food processor, process cookies to fine, even crumbs, about 30 seconds (you should have about 1 cup). Add sugar and pulse 2 or 3 times to incorporate. Add warm melted butter in slow, steady stream while pulsing; pulse until mixture is evenly moistened and resembles wet sand, about ten 1-second pulses. Transfer mixture to 9-inch springform pan; using bottom of ramekin or dry measuring cup, press firmly and evenly into pan bottom, keeping sides as clean as possible. Bake until fragrant and golden brown, 15 to 18 minutes. Cool on wire rack to room temperature, about 30 minutes. When cool, wrap outside of pan with two 18-inch square pieces heavy-duty foil; set springform pan in roasting pan.
2. FOR THE FILLING: While crust is cooling, process 1/4 cup sugar and lemon, lime, and orange zests in food processor until sugar is yellow and zest is broken down, about 15 seconds, scraping down bowl if necessary. Transfer lemon sugar to small bowl; stir in remaining 1 cup sugar.
3. In standing mixer fitted with paddle attachment, beat cream cheese on low to break up and soften slightly, about 5 seconds. With machine running, add sugar mixture in slow steady stream; increase speed to medium and continue to beat until mixture is creamy and smooth, about 3 minutes, scraping down bowl with rubber spatula as needed. Reduce speed to medium-low and add eggs 2 at a time; beat until incorporated, about 30 seconds, scraping sides and bottom of bowl well after each addition. Add lemon juice, lime juice, orange juice, vanilla, and salt and mix until just incorporated, about 5 seconds; add heavy cream and mix until just incorporated, about 5 seconds longer. Give batter final scrape, stir with rubber spatula, and pour into prepared springform pan; fill roasting pan with enough hot tap water to come halfway up sides of springform pan. Bake until center jiggles slightly, sides just start to puff, surface is no longer shiny, and instant-read thermometer inserted in center of cake registers 150 degrees, 55 to 60 minutes. Turn off oven and prop open oven door with potholder or wooden spoon handle; allow cake to cool in water bath in oven for 1 hour. Transfer springform pan without foil to wire rack; run small paring knife around inside edge of pan to loosen sides of cake and cool cake to room temperature, about 2 hours.
4. FOR THE CITRUS CURD: While cheesecake bakes, heat lemon juice, lime juice, orange juice, and orange zest in small nonreactive saucepan over medium heat until hot but not boiling. Whisk eggs and yolk in medium nonreactive bowl; gradually whisk in sugar. Whisking constantly, slowly pour hot juice into eggs, then return mixture to saucepan and cook over medium heat, stirring constantly with wooden spoon, until mixture registers 170 degrees on instant-read thermometer and is thick enough to cling to spoon, about 3 minutes. Immediately remove pan from heat and stir in cold butter until incorporated; stir in cream and salt, then pour curd through fine-mesh strainer into small nonreactive bowl. Cover surface of curd directly with plastic wrap; refrigerate until needed.
5. TO FINISH THE CAKE: When cheesecake is cool, scrape citrus curd onto cheesecake still in springform pan; using offset icing spatula, spread curd evenly over top of cheesecake. Cover tightly with plastic wrap and refrigerate for at least 4 hours or up to 24 hours. To serve, remove sides of springform pan and cut cake into wedges. (If desired, to remove cheesecake from springform pan bottom, slice thin metal spatula between crust and pan bottom to loosen, then slide cake onto serving plate.)