Preheat the oven to 350°F (180°C).
Grease or line a round cake pan (about 9 inches in diameter) with parchment paper.
Separate the egg whites from the yolks, placing them in two separate mixing bowls.Whisk the egg yolks and sugar together until the mixture becomes pale and fluffy. Add the fromage blanc and mix until smooth and well combined.
Sift in the cornstarch and baking powder to prevent lumps. Mix well.
Wash the lemon and finely grate the zest. Juice only half of the lemon. Add the juice and zest to the batter and mix well.
In a separate bowl, beat the egg whites until stiff peaks form. Gently fold them into the batter using a rubber spatula, lifting the mixture as you go to keep it light and airy.
Pour the batter into the prepared cake pan and bake for 30–40 minutes.
Allow the cake to cool completely before removing it from the pan.
