Soften the cream cheese at room temperature and mix with mascarpone.
Add the sweetener in two additions and mix well to combine.
In another bowl, combine room temperature eggs, 5ml lemon juice, 3 drops of vanilla oil, and 0.5g salt.
Add the egg mixture to the cheese bowl in two parts, mixing each time.
Sift in the starch.
Preheat oven to 230°C for 10 minutes, then bake at 230°C for 20 minutes.