Preheat the oven to 450°F and set an oven rack in the middle position. Line a baking sheet with aluminum foil or parchment paper for easy cleanup, and spray with nonstick cooking spray.

In a small bowl, whisk together the mustard, melted butter, honey, ¼ teaspoon salt, and pepper. Set aside.

In another small bowl, mix together the panko, pecans, parsley (if using), and remaining ¼ teaspoon salt.

Spoon the honey-mustard mixture evenly over the salmon fillets. (Don't worry if it drips down the sides a little.) Sprinkle the panko-pecan mixture over the glaze, pressing it lightly so it adheres.

Bake for 7-10 minutes per inch of thickness in the 450 degree oven until it reaches 145 at the thickest part as read by an instant read thermometer. (This is the minimum temperature the FDA reccommends as it will kill all fish born bacteria. Cook it further if you prefer your salmon well done (If you find that the topping is browning more than you’d like before the fish is cooked through, loosely cover the salmon with foil.) Serve hot or at room temperature. (Note that if your salmon has skin, it may stick to the foil; to remove the fish from the pan, slide a thin spatula between the skin and the flesh, leaving the skin behind.)

Make Ahead: The salmon can be glazed, coated with the panko-pecan mixture, and refrigerated up to 3 hours ahead of time.