Line 8-inch pan with parchment paper
Preheat oven to 150°C (300°F)
Set up hot-water bath by filling a large pan halfway with hot water
Heat cream cheese, butter, and milk together until smooth
Mix in flour, cornstarch, and salt
Add egg yolks one at a time to the mixture
Whip egg whites, gradually adding sugar, until soft peaks form
Add ⅓ of the whipped whites to the base and fold gently to lighten
Add remaining whites in 2 batches, folding just until no streaks remain
Pour batter into lined pan and tap lightly to release bubbles
Place pan into the hot-water bath
Bake for 30 minutes with oven closed
Crack oven door open slightly and bake for 20 minutes
Close oven door and bake for 20 more minutes
Check that top is lightly golden and center jiggles softly with springy texture
Flip out gently, then flip upright
