Begin by preheating your oven to 400 degrees F.
Grease a 9x13-inch baking dish generously with nonstick cooking spray and set it aside
In a small saucepan over medium heat, combine soy sauce, brown sugar, apple cider vinegar, garlic, sesame oil, salt, and pepper.
In a separate small bowl, whisk together water and cornstarch until smooth, then gradually whisk this mixture into the saucepan.
Bring the sauce to a boil and let it boil for 1-2 minutes, or until it starts to thicken.
Reserve 1⁄4 cup of the sauce and set it aside for later.
Place the salmon fillets in the prepared baking dish.
Pour the teriyaki sauce over the salmon, ensuring you reserve 1/4 cup of the sauce.
Bake the salmon in the preheated oven for approximately 15 minutes, or until the salmon flakes easily and is fully cooked.
Remove the baked salmon from the oven and drizzle the reserved 1/4 cup of teriyaki sauce over the top.
Garnish the salmon with finely chopped green onions and a sprinkle of sesame seeds. Enjoy!