Mix egg yolks with yogurt, lemon zest, and juice. Add in cornstarch and flour into the yolk mixture and whisk into a smooth batter. Set aside.

Beat egg white with a pinch of salt until foamy. Start adding in sugar, while still working with a mixer. Stop when firm to stiff peaks form.

Fold in egg whites into the batter gradually.

Pour into an 18 cm cake pan and place it into the baking pan filled with hot water. Bake at 150C/302F for 60 minutes.

Once cake is cooled, either top it with icing sugar or lemon glaze.

Optional lemon glaze: Whisk powdered sugar and milk until smooth. You may test the consistency using a spoon and add more milk if it's too thick.

Whisk in lemon juice. Drizzle the glaze over a cooled cake. The glaze will harden as it sets (~ 30mins).