1 - Beat the eggs, sugar and vanilla sugar until light and fluffy.

2 - I beat this in a stand mixer on medium-high speed for about 10 minutes.

3 - Sift the flour and cornstarch and add to the mixture.

4 - Fold this gently into the mixture; you don’t want all the air you whipped in to disappear.

5 - Pour the batter into a greased baking pan.