Preheat oven to 350 degrees F. Coat an 8x8 inch baking pan with non-stick cooking spray.
Open package of brownie mix and remove 1 cup. Place the remaining mix in a large bowl. Add the 1 cup red velvet cake mix to the bowl along with the egg, oil and water. Stir until well blended.
Pour batter into prepared pan. Bake for 28-33 minutes or until toothpick inserted in center comes out clean.