Heat oven to 375°F. Remove and discard giblets from chicken. Rinse chicken inside and out with cold water; drain. Pat dry with paper towels. Rub chicken with seasoned salt, marjoram and pepper. In shallow roasting pan, place chicken. Insert ovenproof meat thermometer so tip is in thickest part of inside thigh and does not touch bone. Bake 45 minutes.
Arrange squash, cut side up, around chicken. Bake 30 minutes longer.
In small bowl, mix pineapple with juice, maple syrup, soy sauce and mustard until well blended. Spoon about 1 cup pineapple mixture over chicken and squash. Bake 15 to 30 minutes longer or until thermometer reads 180°F and legs move easily when lifted or twisted, and squash is tender, basting chicken and squash with pan juices once.
Remove chicken and squash from pan; cover to keep warm. Pour drippings from pan into medium saucepan. Add remaining pineapple mixture; mix well. Cook over medium heat 5 to 10 minutes or until mixture is reduced slightly, stirring occasionally. Serve pineapple mixture with chicken and squash.