1 box chocolate cake mix
1 (8 oz.) pkg. cream cheese, softened
2 tbsp. butter, softened
1 tbsp. cornstarch
1 (14 oz.) can Eagle condensed milk (NOT evaporated)
1 egg
1 tsp. vanilla extract
1 (16 oz.) can prepared chocolate frosting

Preheat oven to 350 degrees. Prepare cake mix as package directs. Pour batter into well-greased and floured 15 x 10 inch jelly roll pan. In a small bowl, beat cheese, butter and cornstarch until fluffy. Gradually beat in condensed milk, then egg and vanilla until smooth. Spoon evenly over batter. Bake 20 minutes or until wooden pick inserted in center comes out smooth and clean. Cool and frost.