Beat eggs with sugar until frothy. The crowd must have a good standing. Sift the flour, cornstarch and baking powder. Lemon zest over it. Carefully mix in the flour with a wooden mixing spoon (preferably with a hole). Carefully fold in the butter, also boiling hot. Pour into a springform pan lined with paper.
Bake at approx. 160 ° C for about 30-40 minutes, depending on the oven. After baking, turn the base with the springform pan onto a wire rack and allow to cool.