01 - In a large bowl, whisk together olive oil, lemon juice, smoked paprika, garlic powder, onion powder, oregano, thyme, cayenne pepper, black pepper, salt, and brown sugar until well combined.
02 - Add the chicken thighs to the marinade and toss until thoroughly coated. Cover and refrigerate for at least 30 minutes (up to 8 hours for deeper flavor).
03 - Preheat a grill or grill pan to medium-high heat. Lightly oil the grate.
04 - Remove chicken from the marinade, letting excess drip off. Grill the thighs for 6-8 minutes per side, or until the internal temperature reaches 165°F and the outside is charred and crispy.
05 - Transfer to a plate, let rest for 5 minutes, then garnish with fresh parsley and serve with lemon wedges.