Base:

1 pkg. chocolate chip cake mix
1/2 c. (1 stick) butter
1 egg

Filling:

1/3 c. milk
6 oz. semi-sweet chocolate chips
2 (3 oz. ea.) pkgs. cream cheese
1/2 tsp. vanilla
1 egg, slightly beaten

Heat oven to 350°F. Grease 13x9-inch pan. In a large bowl, combine all base ingredients at low speed until well blended and no longer crumbly. Reserve 1 cup mixture for topping. Press remaining base into bottom of prepared pan.

In medium saucepan, combine milk, chips and cream cheese. Cook over low heat until chocolate chips and cream cheese are melted. Remove from heat. Stir in vanilla and egg. Blend well. Pour over base. Drop reserved 1 cup base mixture by teaspoons randomly over filling.

Bake at 350°F for 25 to 30 minutes or until topping is golden brown and filling set. Cool completely. Cut into 36 bars. Store in refrigerator.