Mix the butter, sugar, vanilla and lemon zest until frothy. Then stir in the flour, cornstarch, milk and lemon juice. Roll out the dough approx. 2-3 mm thick and refrigerate.
Cut out with an egg-shaped biscuit shape and cut a small round hole out of half of the biscuits. Place on a baking sheet lined with baking paper.
Bake the biscuits in a preheated oven at 200 ° C for approx. 11 minutes and then let them cool down.
Brush half of the biscuits (the ones with the holes) with lemon icing and let them dry. Put a dollop of lemon curd on the other half (see recipe in my profile). Then put 2 different biscuits together - the fried eggs are ready.
It is best to store in the refrigerator until consumption - if only because of the lemon curd.