Preheat oven to 325 degrees F. In a food processor, with knife blade attached, pulse pecans and 1 1/4 cups confectioners' sugar until pecans are finely ground. Add butter and vanilla; pulse until butter is incorporated. Add flour and salt, and pulse until evenly moistened. Transfer dough to medium bowl; stir in chocolate chips.

With floured hands, shape dough by heaping teaspoons into 1-inch balls. Place balls, 1 inch apart, on an ungreased rimmed baking sheet.

Bake cookies 20 to 22 minutes or until bottoms are lightly browned. Transfer cookies to wire rack to cool slightly.

Place the remaining 1 cup confectioners' sugar in a medium bowl. While still warm, gently roll cookies, one at a time, in sugar to coat. Place cookies on a wire rack to cool completely. When cool, gently dust, through a sifter, cookies with sugar again.

Repeat with remaining dough and sugar. Store cookies in a tightly covered container for up to 3 weeks.