Pound each chicken breast 1/2 inch thick. Spread each with 1 tbsp of the cream cheese. Roll up and secure each with 2 wooden toothpicks. Dip in the dijon mustard and roll in the dark brown sugar. Place in a baking dish sprayed with nonstick cooking spray. Sprinkle with pecans. Bake at 300 degrees for 45 to 60 minutes or until the chicken is cooked through.