Preheat the oven to 400°F (200°C).
In a mixing bowl, combine the brown sugar, soy sauce, Dijon mustard, olive oil, garlic powder, black pepper, and salt. Whisk until smooth to create a glaze.
Place the salmon fillets skin-side down in a baking dish. Pour the glaze over the salmon, ensuring that each piece is well coated.
Let the salmon marinate in the glaze for about 5 minutes while the oven preheats.
Once the oven is ready, cover the baking dish with aluminum foil (if desired) and bake for 12-15 minutes, or until the salmon flakes easily with a fork and reaches an internal temperature of 145°F (63°C).
For a caramelized finish, you may broil the salmon for an additional 2-3 minutes after baking.
Remove from the oven, garnish with chopped parsley if desired, and serve immediately.