Realization:

1. Separate the egg whites from the egg yolks. Then whisk whites until they are stiff. Gradually add sugar while mixing and beating the mass thoroughly.

2. Then gradually add the yolks and beat everything to a fluffy mass.

3. In a separate bowl, sift the wheat flour, potato flour, baking powder and vanilla sugar. Mix everything up.

4. Add the flour to the whipped ingredients. Blend everything.

5. At the end, add 4 tablespoons of mayonnaise and lemon zest and mix again until smooth.

6. Pour the mixture into a greased and floured baking pan. Level the surface and put in a preheated oven.

Bake at 180 degrees C for about 40 – 45 minutes until a stick is dry.

For Lemon icing: Squeeze the lemon and combine with the powdered sugar to make the frosting. Pour over the cooled cake and decorate as you like.