1. Preheat oven to 450 F. Place chicken in roasting pan; tuck wings underneath. Sprinkle chicken with salt, pepper and cayenne pepper.
2. Cut lemon in half, squeeze juice over chicken and place lemon halves into cavity of chicken. Place chicken in oven and roast 15 minutes.
3. Reduce heat to 350; roast an additional 50 minutes or until meat thermometer registers 180 F when inserted into thickest part of thigh.
4. Remove chicken from pan, cover with foil and set aside. Pour off excess fat from pan drippings.
5. Place roasting pan on stove over medium heat; stir in chicken broth, lemon zest, cranberries, kumquats, horseradish and maple syrup. Bring to a simmer; cook until cranberries pop, stirring often. Reduce heat to low.
6.Slice chicken and arrange on serving platter. Stir butter into sauce; pour into a bowl and serve with chicken.