Preheat the oven to 350 degrees F and lightly spray a casserole dish with cooking oil.
Place the salmon fillet in the casserole dish and brush lightly with avocado oil. Sprinkle salmon with paprika, garlic powder, dried parsley, and sea salt.
Pour the stone ground (or whole grain or Dijon) mustard over the salmon and spread with a knife or spoon until the flesh is evenly coated in mustard. Note: for maple mustard salmon, mix mustard and pure maple syrup in a small bowl to spread over the salmon.
Bake on the center rack of the preheated oven 15-20 minutes. Switch the oven to the high broil setting and broil 5 minutes, or until salmon is crispy. Salmon is fully cooked when it reaches an internal temperature of 145 degrees Fahrenheit. Insert a digital thermometer into the thickest part of the fish to check for doneness. Serve with lemon wedges and your favorite side dishes.