In 2-cup cellophane bag, layer ingredients in the following order: half of the flour, the sugar, espresso powder, remaining flour, and pecans. Seal; store in a cool, dry place for up to 1 month.
To make cookies:
Preheat oven to 325 degrees F. Empty cookie mix from bag into medium bowl. Sprinkle with 1 teaspoon vanilla. Using pastry blender, cut in 1/2 cup butter until mixture resembles fine crumbs and starts to cling. Form mixture into ball and knead until smooth.
On lightly floured surface, roll dough until 1/4 inch thick. Using floured 2-inch round cookie cutter with scalloped edge, cut out dough. Place cutouts 1 inch apart on ungreased cookie sheet. If desired, sprinkle with coarse or granulated sugar. Bake for 15 to 18 minutes or until edges are lightly browned. Transfer to wire rack; cool. If desired, garnish each cookie with pecan half dipped in melted chocolate. Makes about 30 servings.