1Heat oven to 350°F (325°F for dark or nonstick pan). Spray 13x9-inch pan with cooking spray.
2In large bowl, mix all ingredients except cake mix, spread and pecans with whisk; pour into pan. In medium bowl, mix cake mix and spread with fork until blended; spoon tablespoonfuls of batter randomly over mixture in pan. Sprinkle with pecans.
3Bake 48 to 55 minutes or until toothpick inserted in center comes out clean. Cool on cooling rack 30 minutes. Serve warm with whipped topping or vanilla ice cream, if desired. Store covered in refrigerator.