In a large bowl or container, whisk together the soy sauce, orange juice, sesame oil, minced garlic, minced ginger, honey, and black pepper until combined.
Add the salmon fillets to the marinade, turning to coat all sides. Cover and refrigerate for about 1 hour (longer for more flavor).
When ready to bake, preheat the oven to 350°F (175°C) and line a baking sheet with aluminum foil.
Place the marinated salmon on the prepared baking sheet, discard excess marinade, and bake one large fillet for about 15 minutes or individual portions for about 10 minutes, until the salmon is opaque and flakes easily with a fork.
Remove from the oven, sprinkle with sesame seeds if using, and serve warm.