How to cook
Beat the soft butter with the sugar until it foams up. Add the yolks, flour, vanilla and lemon peel.
A dough is kneaded from which small pieces are torn and shaped into balls, which are rolled in the egg white and then in the sesame seeds.
Arrange them in a greased pan, with enough space between them.
The sesame biscuits are baked at 356°F (180 degrees) until they're fully baked.
You can use poppy seeds instead of sesame seeds.