1 1/2 cups nuts
1/4 cup granulated sugar
2 cups all-purpose flour
1/4 tsp. salt
16 Tbs. unsalted butter, room temp and cut into small chunks
2 tsp. vanilla extract
1 large egg yolk (optional)
1/2 cup 10X confectioners' sugar
Pulse the nuts in the food processor fitted with a steel blade until half of them look finely chopped and the rest look pulverized. Transfer to another bowl and set aside.
Wipe the bowl of the FP with a paper towel to remove any excess nut oil. Put the granulated sugar in the bowl and process until powdery. Add the flour and salt and pulse just to mix. Add the butter chunks, vanilla and egg yolk if using. Process until the mixture looks damp and begins to clump together. add the nuts and pulse just until combined. Transfer dough to another bowl, cover and refrigerate at least 2 hours, preferably overnight.
Preheat the oven to 325°. Position racks in upper and lower thirds of the oven.
Shape slightly more than level tablespoons of dough into 1 1/4" balls or crescent shapes. Place 2 inches apart on cookie sheets (ungreased). Bake for 22 - 24 minutes or until lightly colored on top and golden brown on bottom. Rotate the cookie sheets from top to bottom and front to back halfway through the bakign time to ensure even baking.
while baking, put the 10X in a bowl. When the cookies are done, let them cool in the pan for 5 minutes, then sieve powdered sugar over the top of each one. Cool completely on a rack before storing. May be stored, airtight, for at least 2 weeks.