8 oz. pkg. cream cheese
2 tbsp. butter
1/4 c. sugar
1 tbsp. cornstarch
1 egg
2 tbsp. milk
1/2 tsp. vanilla

BASE:

1 pkg. devil's food cake mix
3 eggs
1/3 c. oil
1 c. water

Heat oven to 350 degrees. Grease and flour 13 x 9 inch pan. In small bowl, blend oil filling ingredients; beat at highest speed until smooth and creamy. Set aside. In large bowl, blend cake mix, eggs, oil, and water until moistened. Beat 2 minutes at high speed. Pour half of batter into pan. Pour cream cheese mixture over batter, spreading to cover. Pour remaining batter over cream cheese mixture. Bake at 350 degrees for 45 minutes or until toothpick inserted in center comes out clean. Cool completely. Can be frosted.