Preheat oven to 320F

Lay parchment paper in 9in pan, optionally, lay it around the pan as well

Over a small saucepan of boiling water, melt the 250g cream cheese, 220ml heavy whipping cream, and 40g caster sugar

When mixture is completely dissolved, set aside, when it is partly cooled, combine 6 egg yolks, 1tsp vanilla extract, and 1 tbs lemon zest, set aside

In a medium bowl, combine 100g cake flour, 40g corn starch, mix well and sift several times

Start boiling water for water bath

Combine the flour into the egg yolk mixture

Beat the 6 egg whites, and 1/2 tsp lemon juice, slowly adding the 100g caster sugar until soft tips form

Fold 1/3 of the egg whites into the egg yolks mixture gently, then add another 1/3, then the final third.

Pour into the parchment paper laid pan, set into the water bath pan, and add the hot water into the bath (should be at least up to half the cake pan size)

Bake at 390F for 18 minutes, until the top is slightly golden

Reduce the heat to 285F for another 20-30minutes

Turn off the heat, another 30 minutes doors closed, and remove the water bath, open the oven door to cool the cake gradually

Take the cake out, and cool rest of the way before refrigerating

Dust with powdered sugar before serving.