Combine first 5 ingredients in a large bowl. Combine vanilla and next 3 ingredients; add to flour mixture, stirring until well blended (dough will be dry).

Turn dough out onto a lightly floured surface, and knead lightly 7 or 8 times. Shape dough into a 16-inch long roll. Place roll on a greased baking sheet coated with cooking spray, and flatten roll to 1-inch thickness. Bake for 30 minutes. Remove the roll from the baking sheet to a wire rack, and let cool for 10 minutes. Cut the roll diagonally (see photo) into 1/2" slices. Place, cut sides down on a baking sheet. Bake for 10 more minutes. Turn cookies over and bake an additional 10 minutes (cookies will be slightly soft in the center but will harden as they cool). Remove cookies from the baking sheet and let cool completely.