Preheat oven to 350 degrees. Grease and flour (or spray with Baker's Joy) 2 (9") round cake pans. In mixing bowl, combine cake mix, milk, eggs, oil and vanilla. With electric mixer on low speed, beat ingredients for 30 seconds. Continue beating on medium speed for another 2 minutes. Pour batter into prepared pans. Bake for 20-25 minutes or until toothpick inserted in center comes out clean. Cool in pans for 5 minutes. Invert onto cooling rack and cool completely.