Mix together Panko bread crumbs, plain bread crumbs, parmesan cheese, Old Bay seasoning, and garlic salt. Place into a breading tray.
Brush all flesh sides of each salmon filet (not the skin) generously with Dijon mustard.
Press the prepared salmon into the bread crumb mixture, making sure to coat all sides except the skin.
Place skin side down on baking sheet and bake for 15-20 minutes.TIP - Always cook fish with the skin side down. If you place the fish skin side up, the fish will cook and begin to flake, making it fall apart as you lift it.
You can purchase salmon filets individually or buy a whole center-cut salmon and cut them yourself. Be sure to cut into filets while the fish is raw. I recommend center-cut salmon because you get a nice even thickness between each filet after slicing which also means they will cook evenly.