- Preheat oven to 350 degrees.
- Spray a 9 x 13 inch baking dish with non-stick cooking spray.
- Pour prepared brownie batter into the prepared 9 x 13 inch dish.
- In a bowl, beat the cream cheese and sugar together until well blended.
- Beat in the egg, flour, vanilla, and food coloring until well blended and smooth.
- Drop cream cheese mixture by tablespoonfuls evenly on top of batter.
- With knife, cut through mixture a few times to marble.
- Bake as directed on brownie mix box or until toothpick inserted in center comes out almost clean.
- Cool completely, about 1 hour and cut into squares. Store in refrigerator. Serves 15.