Preheat oven to 400° F.
Grease a cookie sheet or line cookie sheet with a silpat liner or parchment paper.
In a mixing bowl, cream together butter, vanilla and 6 tablespoons sugar.
In another bowl, sift together flour and salt.
Gradually add sifted flour to the creamed butter and sugar mixture.
Using a food processor, chop walnuts.
Add chopped walnuts to the dough and mix thoroughly.
Using your hands, roll dough into small balls, about 1 inch in size.
Place on prepared cookie sheet.
Bake for 15-20 minutes. Remove from oven and let rest on cookie sheet for a few minutes to cool down.
Roll baked cookies in powdered sugar to coat them completely.
Store cookies in an airtight container.