1. Preheat oven to 375F.
2. In a mixing bowl add flour and work in butter with your fingers until mixture is the consistency of coarse meal.
3. Stir in walnuts, vanilla, salt, and sugar until blended.
4. Let dough chill in refrigerator for half hour.
5. Preheat oven to 375F.
6. Roll dough out into small balls and flatten, forming into crescent shapes.
7. Place crescents on a baking sheet and bake 15 minutes or until golden brown
8. Remove from oven and let cool slightly. Dust with powdered sugar.