In a medium bowl, mix the breadcrumbs, grated Parmesan, parsley, minced garlic, paprika, cayenne, salt, pepper, and lemon juice. Stir well so that the flavors distribute evenly through the dry ingredients. This mix should feel slightly moist due to the lemon juice, but not clumpy.
Crack the egg into a small bowl and beat it with a fork until smooth. This will help the crust stick to the salmon. If the egg isn’t fully beaten, the coating may slide off while baking. Set this bowl next to your breadcrumb mixture to create a quick coating station.
Pat the salmon fillets dry using a paper towel. Dip each fillet into the egg, coating it evenly, then press it into the breadcrumb-Parmesan mix. Press the coating down slightly to help it stick, making sure the salmon is completely covered on all sides for a good crust.
Spray a baking dish lightly with cooking spray, and place the coated salmon fillets inside. Then, spray the tops of the fillets with a light layer of cooking spray as well—this helps crisp the crust in the oven. Bake in a preheated oven at 200°C (about 400°F) for 12–15 minutes or until golden and flaky inside.
Once done, remove the salmon from the oven and let it rest for a minute or two. Serve hot with a wedge of lemon for extra zing. You can pair it with roasted vegetables, mashed potatoes, or a light green salad for a balanced meal.