To prepare chicken, remove and discard giblets and neck from chicken. Rinse chicken with cold water; pat dry. Trim excess fat.
Place chicken, breast side up, on a broiler pan coated with cooking spray.
Bake at 375 for 1 hour and 20 minutes or until a thermometer inserted into meaty part of thigh registers 17
Let chicken stand 10 minutes. Discard skin.
To prepare stuffing, cook oats in a large nonstick skillet over medium-high heat 10 minutes or until lightly toasted and fragrant, stirring frequently. Spoon into a medium bowl.
Melt butter in pan over medium-high heat.
Add leek and fennel; saut 8 minutes or until tender.
Add leek mixture, broth, and remaining ingredients to toasted oats, and stir well to combine. Spoon mixture into a 1-quart casserole dish coated with cooking spray.
Bake at 375 for 20 minutes or until thoroughly heated.