Heat the oven. Preheat to 400°F (200°C). Line a sheet pan with foil or parchment for easy cleanup and lightly oil it.
Prep the salmon. Pat fillets dry with paper towels. Place them skin-side down on the pan.
Season the tops with salt and pepper.
Make the glaze. In a bowl, mix melted butter, mayonnaise, minced garlic, lemon zest, Parmesan, and parsley. If using, stir in panko for crunch. Add a pinch of red pepper flakes if you like a little heat.
Spread it on. Spoon the glaze evenly over each fillet, pressing lightly so it adheres.
Leave a thin border around the edges so it doesn’t spill too much onto the pan.
Bake. Roast for 9–12 minutes, depending on thickness. Thicker center-cut fillets may need closer to 12 minutes.
Broil to finish. Switch to broil for 1–2 minutes to brown the top. Watch closely so the cheese doesn’t burn.
Check doneness. The salmon should flake easily and be just opaque in the center.
Target an internal temperature of 125–130°F for moist, medium doneness.
Rest and serve. Let it rest 2 minutes. Squeeze with fresh lemon juice and serve with a simple side like roasted asparagus, steamed green beans, or a light salad.