Combine flour, yeast and salt and mix in a planetary mixer with the soft butter.

Work until it is "sablè", that is, with a consistency similar to Parmesan.

Add the icing sugar.

When the sugar is blended, add the yolk.

Create a homogeneous dough and let it rest for at least 30 minutes in the refrigerator.

Bake in the oven at 180 ° C