01 -
Preheat the oven to 325°F (160°C). Combine graham cracker crumbs, sugar, and melted butter and mix until evenly moistened. Press firmly into the bottom and slightly up the sides of a 9-inch springform pan. Bake for 10 minutes, then set aside to cool.
02 -
Beat softened cream cheese and sugar on medium speed until completely smooth, about 2 minutes. Reduce speed to low and add eggs one at a time, mixing just until incorporated. Stir in sour cream, lemon zest, lemon juice, and vanilla. Pour over the cooled crust.
03 -
Wrap the outside of the springform pan tightly in two overlapping layers of heavy-duty foil, folding the seam up over the top edge. Place in a large roasting pan and pour hot tap water around it to reach halfway up the sides of the springform pan. Bake at 325°F for 60 to 65 minutes until the edges are set and the center jiggles gently like Jell-O.
04 -
Turn off the oven and crack the door open about an inch. Leave the cheesecake inside for 1 hour. Remove from the water bath, run a thin knife around the edge to release it from the pan, and refrigerate uncovered for at least 4 hours or overnight until completely cold all the way through.
05 -
Whisk egg yolks, sugar, lemon juice, and lemon zest together in a small saucepan. Cook over medium heat, stirring constantly, until thick enough to coat the back of a spoon, about 8 to 10 minutes. Remove from heat and stir in butter until melted and glossy. Cool to room temperature, then spread evenly over the cold cheesecake.
06 -
In a clean, grease-free bowl, beat egg whites and cream of tartar until foamy. Add sugar a tablespoon at a time, beating on medium-high speed until the meringue holds stiff, glossy peaks. Spread or pipe immediately over the lemon curd, sealing the meringue all the way to the edges of the pan.
07 -
Use a kitchen torch in slow circular passes until the peaks are golden brown all over. Alternatively, place the cheesecake on the top rack under a preheated high broiler for 60 to 90 seconds, watching the whole time. Serve right away or refrigerate until ready to slice.