Mix the soft, room temperature butter with 2 tablespoons of powdered sugar until creamy.
Add the egg yolks one at a time and mix well.
Split the vanilla pod with a sharp knife and scrape out the seeds with the blade and add them to the butter cream.
Add the ground walnuts and salt and mix gently.
Incorporate the flour by hand and mix until you get a homogeneous dough, easy to work. If the dough is too crumbly, add another tablespoon of water (or two) if needed to bind it better.
Place the dough on a floured board and form into sticks and them cut into 4-5 cm (1.5 to 2 inch) long pieces.
Shape each piece into a little horn. Repeat until the dough is finished.
You should get around 80 little horns, depending on how thick you make them.
Preheat the oven to 180 C degrees (356 Fahrenheit) and line a large baking tray with baking paper.
Place the crescents on the tray and bake for 15-16 minutes until lightly browned.
Remove from the oven and place them on a cooling rack to cool. After a few minutes, roll them in powdered sugar and serve.
These cookies can be stored in an airtight tin for up to 3-4 weeks.
Enjoy!