Heat oven to 350°F. Grease and flour 13x9-inch pan. In large bowl, beat cake mix, water, oil and egg whites at low speed until moistened. Beat 2 minutes at medium speed. With spoon, stir in crushed cookies. Pour batter into pan.
Bake 30 to 40 minutes or until toothpick inserted in center comes out clean. Cool completely, about 1 hour.
Frost cake with frosting. Garnish with additional cookies if desired.