Heat oven to 400°F. Lightly coat a rimmed baking sheet with cooking spray. Mix jerk seasoning and salt in a small bowl.
Put coconut milk, scallions, garlic, ginger and 3⁄4 tsp jerk seasoning mixture in a large nonstick skillet. Bring to a boil, reduce heat and gently boil 3 minutes to thicken slightly.
Meanwhile, sprinkle both sides of fish with remaining seasoning mixture. Arrange skin side up on baking sheet; coat skin with cooking spray. Bake 8 to 10 minutes until cooked through.
Add carrots and pepper strips to skillet, cover and cook 5 minutes. Stir in spinach and cook until it wilts.
Place snapper on serving plates. Spoon vegetables and sauce over the fish. Garnish servings with cilantro.