***Please realize that the number of eggs and amount of vegetable oil and water may vary depending on what brand of brownies you buy; make sure that you have enough eggs for the brownies and also one egg for the cream cheese mixture.
Preheat oven to 350 degrees Fahrenheit.
Line 18 standard muffin cups with paper baking cups.
Prepare brownie mix according to package directions for cakelike brownies; stir in chocolate chips.
Divide batter evenly into muffin cups.
Beat cream cheese and egg in bowl until well blended.
Add sugar, flour and vanilla; beat until well blended.
Place cream cheese mixture in resealable bag; seal bag. Cut off small corner of bag with scissors.
Pipe cream cheese mixture in concentric circle design on each brownie cup; draw toothpick through cream cheese mixture 6 to 8 times out from center.
Bake 20 to 25 minutes or until toothpick inserted into centers comes out clean.
Cool in pans on wire racks 15 minutes. Remove to racks and cool completely.