Preheat the oven to 300F (150C). Lightly grease an 8-inch (20cm) springform pan and line the bottom and sides with parchment paper. The sides need to be about 4-inch (10 cm) in height.
Separate the whites from the yolks.
Add ¼ cup (50g) sugar over the yolks and mix to combine. Add vanilla extract and lemon zest and mix again to combine.
Add the yogurt and mix it in.
Sift the flour and cornstarch over the yogurt mixture and mix well to combine. Set aside.
Add salt over the egg whites and mix until foamy. Gradually incorporate ¼ cup (50g) sugar.
Continue mixing until soft peaks form.
Gradually incorporate the whipped whites into the egg yolk mixture.
Pour the batter into the prepared pan.
If you are using a springform pan, place it in another pan that doesn’t have a removable base.
Place everything into a larger pan and place in the oven.
Pour hot water until about halfway up the sides of the pan.
Bake for 30 minutes.
Reduce oven temperature to 285F (140C). Continue baking for 25-30 minutes more.
Let cool completely.
Dust with powdered sugar. Enjoy!