Step 1: Preheat your oven to 320°F (160°C). Grease a 7-inch or 8-inch round cake pan and line it with parchment paper, ensuring the paper extends 2 inches above the rim to support the rise.
Step 2: In a double boiler or a bowl over simmering water, combine the cream cheese, unsalted butter, and whole milk. Stir until the mixture is completely smooth and melted.
Step 3: Remove the cheese mixture from the heat. Whisk in the 5 egg yolks one by one until combined. Sift the flour, cornstarch, and salt into the bowl and whisk until smooth.
Step 4: In a clean, grease-free bowl, whip the 5 egg whites until foamy. Gradually add the granulated sugar while continuing to whip until you reach soft, glossy peaks that slightly droop.
Step 5: Fold one-third of the meringue into the cheese batter to lighten it. Gently fold in the remaining meringue in two batches using a spatula, keeping the air bubbles intact.
Step 6: Pour the batter into the cake pan and tap it on the counter to remove large bubbles. Place the pan in a larger roasting dish filled with hot water (1 inch high).
Step 7: Bake for 60-70 minutes. Turn off the oven and leave the cake inside with the door slightly ajar for 15 minutes. Cool on a wire rack before serving or refrigerating.