Heat oven to 350ºF. In large bowl, break up cookie dough. Add chopped almonds; knead into dough with hands until well combined.
Reshape dough into 12-inch log. Using sharp knife, cut log into 24 (1/2-inch) slices. On ungreased cookie sheets, place slices 2 inches apart.
Bake 10 to 12 minutes or until edges are light brown. Cool 2 minutes; remove from cookie sheets to cooling racks.
While cookies are still warm, dust evenly with powdered sugar. Garnish tops with sliced almonds.