Pat the chicken dry. Season on both sides with the salt and pepper.

In a Dutch oven or similar wide, sturdy pot, heat the oil over medium-high. Add the chicken thighs skin-side down in a single layer so the pieces are not touching (you will likely need to cook it in batches; do not crowd the chicken, or it will not crisp properly). Let cook undisturbed for 4 minutes, then move the chicken around a bit so that the skin browns evenly. Continue cooking until deep golden and crisp, about 2 to 4 minutes more. Transfer to your slow cooker, skin-side up. Repeat with the remaining thighs.

Pour the broth into the pot you used to cook the chicken. Stir scraping up the bits stuck to the bottom of the pan (these are FLAVOR and we don’t want to waste them!). Let simmer for 2 minutes. Pour into the slow cooker around the thighs (try not to dump the liquid right on top of the nice, crispy skin).

Zest 1 of the lemons into a small bowl. Add the brown sugar, paprika, thyme, oregano, and garlic powder. Stir to combine, then sprinkle evenly over the chicken.

Cut both of the lemons into wedges, then tuck the wedges around the chicken. Cover and slow cook the chicken thighs on LOW for 4 to 5 hours, until it registers at least 165°F on an instant read thermometer (don't worry if it goes over; thighs are very forgiving; they'll be falling apart tender). Transfer the chicken to a serving plate and sprinkle with parsley. Let rest a few minutes, then enjoy hot with the cooking juices in the slow cooker spooned over the top.