Preheat oven to 425°F with rack in upper third. Lightly oil a shallow baking pan.
Melt butter with hot sauce and 1/4 teaspoon each of salt and pepper over medium heat. Set aside 1/4 cup sauce.
Tosspanko with oil in a bowl. Put salmon, skin side down, in baking pan and sprinkle with 1/4 teaspoon each of salt and pepper, then brush with remaining sauce. Sprinkle panko evenly over top of fish, then bake until panko is golden and fish is just cooked through, 16 to 22 minutes. Serve reserved sauce on the side.
225 calories | 13g fat, 2g carbs, 23g protein