II
The Method
1
Heat the oven to 150–160 °C. Line a 20 cm round cake tin with baking parchment on the base and sides. Set a deep roasting tray large enough to hold the tin in the lower third of the oven and fill it with hot water to a depth of 3–4 cm. This is the bain-marie. The water bath is in position before the batter enters the oven.
2
Beat the cream cheese and butter together until the mixture is completely smooth and uniform — no white lumps of cream cheese remaining, no streaks of butter. Add the egg yolks one at a time, beating after each addition. The base should be pale, slightly glossy, and drop thickly from the beater.
3
Fold the sifted flour and cornflour into the cream cheese base in two additions, using a spatula. Mix only until no dry streaks remain. The batter will be dense and smooth.
4
In a clean bowl, whisk the egg whites to soft peaks, then add the caster sugar in a slow stream and continue whisking to stiff, glossy peaks. The meringue should hold a firm peak that curves only slightly at its tip — neither dry nor under-beaten. This is the Japanese modification that provides all aeration in the finished cake.
5
This is where the dish lives or dies. Fold one-third of the meringue into the cream cheese base using a large spatula, cutting down through the centre and turning the bowl — this lightens the base without deflating the foam. Add the remaining meringue in two additions, folding each with the same motion until just incorporated. No white streaks should remain, but the batter must retain visible volume and body. Over-folding at this stage collapses the foam and produces the dense texture of a Western cheesecake — the soufflé-like structure cannot be recovered.
6
Pour the batter into the prepared tin and smooth the surface. Set the tin in the water bath in the oven. Bake at 150–160 °C for 60–90 minutes. Do not open the oven during the first 40 minutes. The soufflé structure sets in this period; any temperature drop will cause the cake to collapse.
7
At 60 minutes, begin checking. The surface should be pale gold and even, with no cracks. Gently move the tin: the entire cheesecake should oscillate as a single elastic mass — not a liquid trembling, not immobility. If the centre flows freely it requires further time. If it does not move at all it is overcooked. Continue baking and testing at 10-minute intervals until the elastic jiggle is achieved.
8
Turn off the oven, crack the door slightly, and leave the cheesecake inside for 30 minutes before removing. Rapid cooling causes the surface to crack and the structure to contract unevenly. The cake is ready to unmould when it has settled to just below room temperature; the texture at this point should be simultaneously creamy, airy, and faintly bouncy — no single quality dominant.