Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or lightly grease it with cooking spray.
In a small bowl, mix together the brown sugar, smoked paprika, garlic powder, onion powder, salt, and black pepper.
Pat the salmon fillets dry with paper towels and place them skin-side down on the prepared baking sheet. Drizzle olive oil over the fillets, then sprinkle the spice mixture evenly on top.
Drizzle fresh lemon juice over the seasoned salmon.
Bake in the preheated oven for 12-15 minutes, or until the salmon flakes easily with a fork and reaches an internal temperature of 145°F (63°C).
Remove from the oven and let it rest for a couple of minutes before serving. Serve with lemon wedges on the side.