Preheat oven to 350 F. Coat baking sheet with cooking spray.
Heat the oil in a small saucepan over medium heat. Add the garlic and cook for 1 minute. Reduce heat to low. Stir in the lemon juice, capers, and lemon-pepper seasoning and cook for 5 minutes. Add the sour cream and cook for 5 minutes, or until heated through.
Meanwhile, place the salmon on the prepared baking sheet. Bake for 20 minutes, or until the fish is just opaque. Serve with the sauce.