01 - Preheat oven to 320°F. Line an 8-inch round cake pan with parchment paper. Wrap pan exterior with aluminum foil to create a waterproof seal.
02 - Set a heatproof bowl over simmering water. Combine cream cheese, butter, and milk. Stir continuously until completely smooth. Remove from heat and allow to cool briefly.
03 - Sift together cake flour, cornstarch, and salt. Gradually whisk into the warm cream cheese mixture until fully incorporated and no lumps remain.
04 - Whisk in egg yolks one at a time. Add lemon juice, vanilla extract, and lemon zest. Mix until the batter is smooth and glossy.
05 - Using an electric mixer, beat egg whites on medium speed until foamy. Add sugar in three portions, continuing to beat until stiff glossy peaks form and whites stand upright.
06 - Gently fold one-third of meringue into the cheese mixture to lighten. Add remaining meringue in two batches, using a rubber spatula with careful folding motions to maintain air volume.
07 - Transfer batter to prepared pan. Tap pan firmly against counter three times to release trapped air bubbles.
08 - Place cake pan inside a large roasting pan. Pour hot water into roasting pan until it reaches halfway up the cake pan sides.
09 - Bake for 60-70 minutes until golden brown and set. A skewer inserted into the center should emerge clean.
10 - Turn off oven and leave cheesecake inside with door slightly ajar for 15 minutes. This prevents cracking from thermal shock.
11 - Remove from oven and cool completely in the pan. Refrigerate for minimum 2 hours to set texture before unmolding and serving.