Preheat your oven to 325°F (160°C). Prepare a 9-inch round springform pan by lining the bottom with parchment paper and greasing the sides. Wrap the outside of the pan with two layers of aluminum foil to prevent water from seeping in during the water bath.

In a heatproof bowl, combine the butter, milk, and cream cheese. Place the bowl over a pot of simmering water, ensuring the bottom does not touch the water. Stir gently until the butter and cream cheese melt and the mixture is smooth. Remove from heat and let it cool slightly.

Separate the egg whites from the yolks. In a large mixing bowl, add the egg yolks to the slightly cooled butter mixture and whisk until smooth.

Sift the cake flour and cornstarch into the egg yolk mixture and whisk gently until just combined. Be careful not to overmix. Stir in the vanilla extract.

In a separate clean bowl, add the egg whites and a pinch of salt. Using an electric mixer, whisk on medium speed until foamy. Add the lemon juice and continue whisking.

Gradually add ½ cup (100g) of granulated sugar, one tablespoon at a time, while whisking on medium-high speed. Increase to high speed and whisk until stiff, glossy peaks form.

Add about one-third of the whipped egg whites to the egg yolk batter and gently fold it in with a spatula. This helps to lighten the batter.

Carefully add the remaining meringue to the batter and gently fold it in until just combined, being careful not to deflate the air from the meringue.

Pour the batter into the prepared springform pan and gently tap it on the counter to release any large air bubbles.

Place the springform pan into a larger roasting pan and pour hot water into the roasting pan until it reaches halfway up the sides of the springform pan.

Transfer the roasting pan with the cake to the preheated oven and bake for 60-75 minutes, or until the top is golden brown and a skewer inserted into the center comes out clean or with minimal moist crumbs.

Once baked, turn off the oven and prop the door open slightly. Let the cake cool in the oven for about 15-20 minutes.

Remove the cake from the oven and the water bath. Carefully take off the foil from the springform pan and let the cake cool completely on a wire rack.

Once completely cool, run a thin knife around the edge of the pan before releasing the springform. Dust generously with powdered sugar before serving.