In a large bowl mix the ground walnut, sugar, flour and pinch of salt.
Add the soft butter and 3 tablespoons of cold water and mix (using stand mixer with paddle attachment).
Refrigerate the dough for 2-3 hours.
Preheat the oven to 190℃ (375°F).
Line two baking sheets with baking paper.
Take a piece of the dough (the size of a small walnut) and roll it by hand into a small log and form into a small crescent. Make crescent cookies until you have used up all the dough.
Bake for about 12-15 minutes.
In a small bowl mix the powdered sugar and vanilla powder.
When walnut crescent cookies are still hot, roll them in the powdered sugar and vanilla powder mix and sprinkle with the mix. Let them cool completely.
Notes
Butter can be replaced with margarine which will make the recipe vegetarian.If you are bored of forming the crescent cookies make walnut cookies from the remaing dough.