Combine first 6 ingredients in a small saucepan. Scrape seeds from vanilla bean; stir seeds into broth mixture, reserving the bean for another use. Bring to a boil. Reduce heat, and simmer until reduced to 1/2 cup (about 20 minutes). Stir in 1/4 teaspoon salt.
Arrange chicken in a single layer in the bottom of a roasting pan coated with cooking spray. Sprinkle chicken evenly with remaining 1/2 teaspoon salt and pepper. Bake at 450° for 10 minutes.
Brush half of broth mixture over chicken; bake 5 minutes. Brush remaining broth mixture over chicken; bake 15 minutes or until a thermometer registers 180°. Garnish with orange rind, if desired.
Delicious! I made a few minor substitutions--I used a blood orange for the juice and rind, and used half regular balsamic vinegar, and half blood orange balsamic vinegar. Paired with asparagus cooked in blood orange balsamic vinegar, blood orange juice, shallots, garlic, and a pinch of vanilla-scented sugar. Absolutely awesome! Can't wait to share with friends and family!