Grease and line an 8-inch waterproof/leakproof springform tin. Wrap the outside of the pan with tinfoil. Line a deep baking tray with kitchen cloth, creating a water bath for baking.

Melt together the cream cheese, butter, and milk in the microwave for roughly 1 ? minutes. Whisk until there are no more lumps.

Whisk in the egg yolk, lemon juice, vanilla extract, and half the sugar.

Place a sieve over the bowl and add the cake flour, corn starch, and salt. Sieve into the cream cheese mixture and whisk until there are no lumps. Set aside.

Using a stand mixer or hand mixer, whip the egg whites until they start to take shape. Add the cream of tartar. Gradually add the remaining sugar while whipping until glossy and holding a stiff peak.

Fold 1/3 of the meringue into the cream cheese batter to loosen the mixture. Gently fold in the remaining meringue until blended.

Pour the cheesecake batter into the prepared cake pan. Place the cake pan in the larger dish and pour boiling water into the water bath until it reaches halfway up the sides of the cake pan.

Bake on the bottom rack in a preheated 400?F (200?C) oven for 18 minutes, then lower to 320?F (160?C) for 12 minutes. Turn off the oven and open the door slightly for 30 minutes. Remove from the oven to cool at room temperature.

Turn out the cheesecake onto a cake plate and serve. Store in the fridge in an airtight container for up to 3 days.