Prepare the Spice Mix: In a small bowl, combine the smoked paprika, garlic powder, onion powder, thyme, oregano, cayenne pepper, black pepper, and salt. Mix well.
Season the Salmon: Pat the salmon fillets dry with paper towels. Brush each fillet with olive oil or melted butter on both sides. Generously rub the spice mix onto the salmon, pressing lightly to help it adhere.
Cook the Salmon: Heat a large skillet (preferably cast-iron) over medium-high heat until very hot. Place the salmon fillets in the skillet, flesh side down if skin-on, and cook for 3-4 minutes per side, or until the outside is blackened and the fish flakes easily with a fork.
Serve: Remove from the skillet and serve with lemon wedges and a sprinkle of fresh parsley if desired.