Heat oven to 350°F (325°F for dark or nonstick pans). Grease or spray two 9-inch round cake pans. In large bowl, beat cake mix, water, oil and eggs with electric mixer on low speed 30 seconds, then on medium speed 2 minutes, scraping bowl occasionally. Divide batter between pans. Bake as directed on box for 9-inch rounds. Cool 10 minutes; remove cakes from pans to cooling racks. Cool completely, about 30 minutes. For easier handling, refrigerate or freeze cakes 30 to 60 minutes or until firm.