1. Bring 4 cups water to a boil in a large Dutch oven over medium-high heat. Add kosher salt and molasses. Reduce heat to low, and simmer, stirring occasionally, 2 to 3 minutes or until salt and molasses dissolve. Transfer to a very large bowl; add ice and next 4 ingredients. Let stand, stirring occasionally, 30 minutes or until mixture cools to room temperature. Cover and chill 30 minutes to 1 hour or until cold.
2. Submerge chicken in cold brine. Cover and chill 6 to 8 hours.
3. Preheat oven to 400°. Remove chicken from brine; rinse and pat dry. Sprinkle with garlic salt.
4. Heat 1 Tbsp. oil in a 14-inch nonstick or cast-iron skillet over medium-high heat. Add 4 unpeeled garlic cloves, 1 thyme sprig, and half of chicken. Cook 5 minutes or until skin is browned and crisp. (The molasses in the brine will brown the skin quickly.) Turn chicken and garlic, and cook 5 minutes or until browned. Remove chicken, and place on a wire rack in a jelly-roll pan. Wipe skillet clean. Repeat with remaining oil, chicken, garlic, and thyme.
5. Bake chicken, skin side up, at 400° for 10 to 20 minutes or until a meat thermometer inserted into thickest portion registers 165°. (Breasts will cook faster than legs, so check for doneness after 10 minutes.) Cover with foil. Let stand 10 minutes before slicing. Serve with Roasted Chicken Jus, if desired.
*8 chicken leg quarters or 8 chicken breasts, airline cut, may be substituted.
Note: We tested with Diamond Crystal Kosher Salt.