Chocolate Cream Cheese Filled Cake

1 package. Pillsbury plus, devils food cake mix,or any brand
1 cup water
1/3 cup oil
3 eggs

1/4 cup sugar
1 tablespoon cornstarch
2 tablespoons margarine or butter
2 tablespoons milk
1/2 teaspoon vanilla
8-oz. cream cheese, softened
1 egg

1 can chocolate fudge ready-to-spread frosting or any chocolate frosting

Heat oven to 350 degrees. Grease and flour a 13x9 pan.

In small bowl, blend all filling ingredients at highest speed until smooth
and creamy. Set aside.

In large bowl, blend base ingredients until moistened. Beat 2 minutes at
highest speed.

Pour half of batter into prepared pan.

Pour cream cheese mixture over batter, spreading to cover.

Pour remaining batter over cream cheese mixture.

Bake at 350, for 45 to 55 minutes or until toothpick inserted in center
comes out clean.

Frost after completely cooled, and refrigerate.