Preheat oven to 350 degrees F (175 degrees C). Spray 15 x 10 inch jelly roll pan with nonstick cooking spray.
Prepare pudding as directed in large mixing bowl. Whisk in the cake mix. Stir in chocolate chips.
Pour batter into prepared pan. Sprinkle with mini M and M's, if desired. Bake for 25 to 30 minutes, or until middle of brownies spring back up when touched. Cool completely and cut into 30 squares.
