Preheat oven to 425 degrees.
Line a baking sheet with foil.
Mix the 2 tbsp light brown sugar, 1/2 tsp paprika, 1/2 tsp garlic powder, 1/4 tsp cayenne pepper, 1 tsp kosher salt and a generous amount of freshly ground black pepper in a small bowl.
In another small bowl, mix the 1/4 cup panko bread crumbs with the 1/2 cup parsley, 2 tbsp unsalted butter, 1/4 tsp of kosher salt and a few grinds of black pepper.
Place the 1 1/2 lbs skin-on salmon fillet, skin-side down on the prepared baking sheet and spread the surface with the 1 tbsp Dijon mustard.
Press the brown sugar mixture all over the salmon, then top with the breadcrumb mixture.
Crimp all four sides of the foil to create a border around the salmon. This will help collect the juices so they don't spread and burn.
Bake until the breadcrumbs are golden brown and the salmon is firm and flakes easily when pressed, about 15-18 minutes.
Cut into 4 equal portions for serving.
