Preheat oven to 350°. Line 2 baking sheets with parchment paper. Set aside.
Toast Nuts: Place nuts on baking sheet and bake for about 8 minutes, or until lightly brown and fragrant. Cool. Once the nuts have cooled completely place them, along with 2 tablespoons of the flour from the recipe, into food processor, fitted with a metal blade, and process until they are finely ground (but not a paste). Set aside.
In bowl of your electric mixer (or with a hand mixer), cream butter and sugar until light and fluffy (about 2 minutes). Beat in vanilla extract. Add remaining flour and salt and beat until combined. Stir in nuts. Cover and refrigerate dough for about 1 hour or until firm. Form dough into 1 inch balls and place them 2 inches apart on prepared baking sheets. Bake for about 12 – 15 minutes, or until edges of cookies start to brown. Remove from oven and place on wire rack to cool for about 5 minutes. Meanwhile, line another baking pan or tray with parchment or wax paper. Sprinkle about 1/2 cup of the confectioners? sugar on the bottom of the pan and then place slightly cooled cookies on top of the sugar. Place the remaining 1/2 cup of sugar in a fine strainer or sieve and then sprinkle the tops of the cookies (or you can just roll the cookies in the sugar). Store in an airtight container. Makes about 3 dozen cookies.
The secret to making these cookies taste their best is to use high quality butter and pure vanilla extract. Butter in the States is graded according to flavor, color, texture, aroma and body and one easy way to tell the quality of the butter is by the letter code or numerical number listed on the butter?s package. The highest grade is AA (93 score), then A (92 score), followed by B (90 score). In choosing vanilla extract, the first thing to do is to make sure that it is labeled ?pure?. There are quality brands to be found in your local grocery store. Just stay away from the ones labeled ?imitation? vanilla extracts as they are made with synthetic vanilla (from glycoside found in the sapwood of certain conifers or from coal extracts) and leave a bitter aftertaste.