1Heat oven to 350°F (325°F for dark or nonstick pan). Grease bottom only and lightly flour 13x9-inch pan, or spray bottom with baking spray with flour. In medium bowl, mix crust ingredients. Sprinkle evenly on bottom of pan; press gently.
2In large bowl, beat cake ingredients with electric mixer on low speed 30 seconds, then on medium speed 2 minutes, scraping bowl occasionally. Pour batter over crust.
3Bake 34 to 39 minutes or until light golden brown and top springs back when touched lightly in center. Cool completely, about 2 hours. Frost with whipped topping; sprinkle with additional lime peel. Store loosely covered in refrigerator.