HEAT oven to 400°F.
SPREAD chicken with 2 Tbsp. marmalade. Empty coating mix into shallow dish. Add chicken; turn to evenly coat both sides of each breast. Place in 13x9-inch baking dish.
BAKE 25 min. or until chicken is done (165ºF).
MIX dressing and remaining marmalade. Add to spinach; toss to coat. Place on 4 serving plates. Top spinach on each plate with 1 sliced chicken breast and 1/4 of the oranges.