Preheat oven to 350°F. Line the bottom of a 9-inch springform pan with parchment paper and spray the bottom and sides with nonstick spray. Set aside.: You should notice the oven beginning to hum as it warms and the air inside becoming steadily warmer. Properly lining the pan ensures an easy release and prevents sticking. One common mistake is skipping the parchment, which can make unmolding messy and might tear the crust when releasing the ring.
Use a food processor to crush the vanilla wafer cookies to crumbs, about 1 minute.: The sound of the processor will change from a steady grind to a finer whir as the cookies become uniform crumbs, and you will see a sandy texture. Even crumbs compact more reliably and bake evenly; if you leave large pieces they can create weak spots in the crust.
Add in the salted butter and pulse to combine. You should have a mixture with the consistency of wet sand.: Visually the mixture should transform from dry crumbs to a glossy, sand like clump. The melted salted butter coats each crumb, which helps them bind when pressed into the pan. If the mixture feels too greasy, you likely added too much butter; if it is too dry, the crust will be crumbly.
Press the crust into the springform pan.: Press firmly so the base becomes compact and even, using the bottom of a measuring cup to smooth it. You want a firm, even layer with no thin spots that would break apart when sliced. If you press unevenly you may bake sections differently leading to textural contrasts.
Bake the crust for 10-12 minutes, or until it just begins to brown.: The aroma will shift to a toasty, slightly caramelized scent, and the edges should become just a shade darker. This short bake sets the crust so it supports the filling. Baking too long will make the crust overly hard and dry, while underbaking risks a soggy base.
Reduce the oven to 300°F, remove the crust from the oven, and allow the crust to cool completely.: The oven will settle into a lower, steady warmth, and the cooled crust should feel firm to the touch. Cooling prevents the filling from melting the crust and helps maintain a neat edge. If you pour the filling into a hot crust, the butter can loosen and cause separation.
While the crust is cooling, prepare a water bath by placing a lint free towel, folded, in the bottom of a roasting or large baking pan. You want a pan large enough for the springform pan to fit comfortably with a little space on all sides.: The towel acts as a cradle that stabilizes the springform pan and keeps it from sliding when the water is added. You'll want a pan that leaves a little breathing room around the springform so steam circulates. Using a pan that is too tight makes it hard to add the water and risks spills.
Heat 4 cups of water in a kettle until boiling, turn off heat and allow it to set while you assemble the cheesecake.: Steam will rise as you pour the water later, so be careful and keep a steady hand. The hot water will create even heat around the cheesecake, preventing sudden temperature shifts. If you use cold water the bath will cool the cheesecake and could lead to cracking.
To make the cheesecake, beat together the sugar and lemon zest in a large mixing bowl with a hand or stand mixer until the sugar is fragrant, about 1 minute.: The aroma should intensify as the oils from the zest release into the sugar, perfuming the bowl. This step is small but important because it distributes concentrated citrus scent throughout the filling. Rubbing the zest into the sugar wastes none of the aromatic oils, so skip it and the lemon will feel faint.
Add in the cream cheese and beat on medium, just until light and fluffy, about 5-7 minutes, depending on the temperature of the cream cheese.: You will see the mixture go from dense and clumpy to smoother and paler, and the sound of the mixer will lighten as the texture softens. Properly softened cream cheese ensures a silky filling; if it is still cold you will see lumps, which means extended beating will incorporate too much air.
Mix in the greek yogurt, lemon juice, and lemon extract until completely combined, about 2-3 minutes.: The batter will become more fluid and glossy, carrying a bright lemon scent. These ingredients balance fat, acid, and flavor to create a stable, flavorful custard. Failing to fully combine can leave pockets of curdled texture after baking.
Beat in the eggs, 1 at a time, on low speed, just until combined. Do not overbeat.: You should see the mixture slightly lighten with each egg, and the batter should look homogenous and velvety. Keeping speed low controls air incorporation, which prevents cracks and a cake like rise. Overbeating introduces large bubbles that can burst and leave craters on the surface.
Wrap the cooled springform pan in aluminum foil and a baking bag, if possible.: This creates a waterproof seal so that the water bath does not seep into the pan and make the crust soggy. Make the foil snug and double wrap the base for safety. A poor seal risks a watery mess and a compromised crust.
Pour the cheesecake mixture into the prepared crust and gently spread into an even layer. Tap the pan gently several times on the counter to pop any air bubbles.: You will see the batter settle into the crust and small bubbles rise and pop, leaving a smooth top. Eliminating air bubbles helps prevent large holes after baking. If you skip tapping, trapped air can expand and create an uneven surface.
Put the cheesecake pan on the folded towel in the roasting or large baking pan and place it all in the oven.: The setup should feel stable and balanced, and the cheesecake should sit level. Proper placement ensures even heat distribution from the water bath. If the pan wobbles, the filling can slosh and bake unevenly.
Carefully pour the hot water into the baking pan, outside the springform pan, until it reaches the middle of the springform pan, at least 1-2 inches. This creates a water bath so that the cheesecake cooks more evenly.: As the water flows you will see steam rise and the oven interior become humid, which softens oven edges and prevents the top from drying. This gentle, surrounding heat produces a creamy texture. Pour too rapidly and you risk splashing water into the cheesecake tin.
Bake for 75-90 minutes, or until the cheesecake has just a slight wiggle in the middle when the springform pan is moved.: The surface will be set and a little golden at the edges, while the center still shivers slightly, like soft gelatin. This state indicates a properly cooked custard that will continue to set as it cools. Overbaking will dry the center and can cause cracks.
Shut the oven and turn it off, allowing the cheesecake to continue cooking as it cools for 30 minutes.: The internal temperature will gently drop, finishing the set without shock. You may hear tiny settling sounds as structure firms. Opening the oven too soon causes a temperature change that can lead to collapse or cracking.
Crack the oven and allow the cheesecake to cool for another 30-45 minutes or until you can comfortably touch the pan without being burnt, before removing it from the oven.: The cooling phase will reduce jiggle and the top will relax into a glossy finish. Slow cooling prevents surface cracks and preserves a silky interior. Rushing this step by chilling immediately can create condensation and sogginess.
Allow the cheesecake to set for 30-45 minutes at room temperature and then spread the lemon curd gently over the top, leaving a 1/4-1/2 inch of space around the edge of the cake for the meringue to seal it in and then cover with plastic wrap and place in the for at least 4 hours or up to overnight.: The curd should sit like a bright jewel on the filling, glossy and slightly thick. Leaving a border keeps the meringue anchored and prevents the curd from running when heat is applied. If the curd is too warm it may melt into the filling, so ensure it is cool before spreading.
Once the cheesecake has refrigerated until set, at least 4 hours, prepare the meringue and preheat the oven to 425°F.: The cold, firmed cheesecake contrasts with the hot oven you will use to toast the meringue briefly. Preheating ensures the meringue browns quickly without overcooking the filling. Omitting the chill results in a softer, less stable surface for the meringue to adhere to.
Prepare the meringue by beating the egg whites and lemon juice together in a large mixing bowl using a hand or stand mixer, until soft peaks form, about 3-4 minutes.: You will see glossy foam forming that grows in volume; it should hold a loose peak when you lift the whisk. The gentle tang of the lemon juice stabilizes the foam and brightens the flavor. If your bowl is not perfectly clean, the whites may fail to whip.
Gradually add in the sugar, 1/2 cup at a time, beating on high until all the sugar has been added.: As you add sugar the meringue should become shiny and denser, and you will feel more resistance on the whisk. Adding sugar slowly allows it to dissolve and yield a stable, glossy foam. Dumping sugar in at once can weigh down and deflate the foam.
Once all the sugar has been added, continue beating until stiff peaks form. This can take another 5-10 minutes. You want a meringue that is stiff enough to hold its shape and stick to the bowl without sliding.: The meringue should stand tall and pointy when the whisk is lifted, and it will glisten. A properly whipped meringue gives a billowy texture that toasts beautifully. Underwhipping yields a collapsing finish, while overwhipping makes it dry and grainy.
Pipe or spread the meringue onto the cheesecake, being sure to place it around the edge of the top so that the curd won’t drip off when heating.: The meringue should cling to the curd and form peaks or swirls that catch the heat and brown attractively. This seal keeps the curd in place and creates a pretty border. If you skimp on the meringue, the curd may bleed when warmed.
Bake for 3-5 minutes or until golden brown.: Watch closely as the meringue will color quickly, turning from snowy white to toasted gold; the aroma becomes slightly caramelized and toasty. This burst of heat transforms the surface to an attractive finish without cooking the interior further. Leaving it in too long will darken too much and can become bitter.
Allow to cool for at least 10 minutes before cutting and serving.: After a short rest the cheesecake firms just enough to slice cleanly, and the meringue settles slightly while remaining soft. Cutting too soon can smear the warm curd and compress the meringue, so patience rewards you with tidy slices.
