In a small saucepan over medium-high heat, whisk together the butter, brown sugar, soy sauce, garlic, ginger, lemon juice, cornstarch, and crushed red pepper. Let it simmer for 2-3 minutes until slightly reduced, then set it aside to cool a bit.
Preheat your oven to 350 degrees Fahrenheit. Line a baking sheet with aluminum foil and place the salmon on top. Sprinkle a pinch of salt over the salmon.
Fold up the sides of the aluminum foil to create a “packet.”
Brush half of the glaze over the salmon.
Bake for 20-25 minutes or until the salmon is thoroughly cooked and reaches an internal temperature of 145 degrees Fahrenheit.
Set the oven to broil and place the salmon under the broiler for 3-5 minutes, or until it turns brown and caramelized. Keep a close eye on it to prevent burning.
Brush the remaining glaze over the salmon and sprinkle with cilantro.