the recipe

Procedure

1. The butter must be pliable.
2. Using the paddle attachment, mix the butter with the flour, vanilla, and lemon zest just until the mixture becomes sandy in texture.
3. Then add the sugar, salt, and egg yolks at low speed, mixing until fully incorporated. The dough will be very fluid.
4. Do not whip the mixture.
5. Let rest in the refrigerator, covered with plastic wrap in contact with the surface, for 10–12 hours.