Preheat oven to 350°F. Lightly grease an 8x8x2-inch pan.
Cookie: In medium bowl, stir together all cookie ingredients until well blended. Press dough evenly into prepared pan.
Bake 28-32 minutes or until toothpick inserted in center comes out clean. Cool completely before topping with glaze.
Glaze: Blend mix and water until smooth.