Preheat your oven to 300°F (150°C). Line a 6-inch round cake pan with parchment paper on both the bottom and sides. This helps prevent sticking and ensures a smooth finish.

Set up a double boiler by placing a heat-safe bowl over a saucepan of simmering water. Add the cream cheese, butter, and milk. Whisk gently until everything is melted and smooth, reaching about 130°F (55°C). Remove from heat.

To the warm cream cheese mixture, whisk in the egg yolks and vanilla extract until smooth and well incorporated.

Sift the cake flour and cornstarch directly into the cream cheese mixture using a fine-mesh sieve. Whisk until smooth, then strain through a sieve to remove any lumps for a silky batter.

In a clean mixing bowl, add egg whites and lemon juice. Using an electric mixer, beat on high until frothy. Gradually add the sugar in three parts while beating. Continue mixing until soft peaks form—when you lift the beater, the peaks should gently fold like soft-serve.

Mix for an extra 30 seconds on low to eliminate large air bubbles.

Fold one-third of the meringue into the yolk mixture to lighten it. Then gently pour the yolk mixture into the rest of the meringue. Carefully fold just until combined—do not over-mix.

Pour the batter from about 5 inches above the pan to pop excess bubbles. Tap the pan lightly on the counter to settle it. Place the cake pan in a larger baking tray and add 1–2 cm of boiling water around it to create a water bath.

Bake at 300°F (150°C) for 30 minutes. Then lower the heat to 230°F (110°C) and bake for another 30 minutes. Finally, raise the temperature to 275°F (135°C) and bake for 13–15 minutes, watching closely to prevent cracking.

Turn off the oven and leave the cake inside with the door cracked for 15 minutes. Remove the water bath and let the cake rest in the oven for another 15 minutes to prevent shrinkage.

Cool completely on a wire rack before dusting with powdered sugar and serving.