Prepare the Ingredients: Preheat your oven to 140°C (284°F). Make sure all your ingredients are at room temperature for best results.

Grease and line a 15 cm (6 inch) round cake pan with parchment paper.

Make the Yolk Dough: In a mixing bowl, sift together the cake flour and corn starch to ensure there are no lumps.

Add the sugar-free yogurt and mix until smooth.

Zest the lemon and add the zest to the mixture. Squeeze the lemon and add the juice.

Add the salt and mix well.

Separate the egg yolks from the whites. Add the egg yolks to the mixture and whisk until fully incorporated.

Prepare the Meringue: In a clean, dry bowl, beat the egg whites until they start to froth.

Gradually add the sugar while continuing to beat the egg whites until stiff peaks form. This should take about 3-5 minutes.

Add the lemon juice and mix until well combined.

Combine Yolk Dough and Meringue: Gently fold a third of the meringue into the yolk dough to lighten the mixture.

Carefully fold in the remaining meringue, making sure to keep as much air in the mixture as possible. Avoid over-mixing to maintain the fluffiness.

Bake the Cake: Pour the batter into the prepared cake pan.

Bake in the preheated oven at 140°C (284°F) for 30 minutes.

After 30 minutes, reduce the temperature to 110°C (230°F) and continue baking for another 60 minutes.

Turn off the oven and let the cake rest in the oven for an additional 10 minutes with the door slightly ajar. This helps to prevent the cake from collapsing due to sudden temperature changes.

Cool and Serve: Remove the cake from the oven and let it cool completely in the pan.

Once cooled, carefully remove the cake from the pan and parchment paper.

For best results, refrigerate the cake overnight. It’s often more flavorful and the texture improves after a day in the fridge.

Serve and Enjoy: Slice the cake and serve chilled. It pairs beautifully with fresh fruit or a light dusting of powdered sugar.