Coat a jelly-roll pan with cooking spray. Place beans on pan, and arrange in a single layer. Drizzle with oil, and toss gently to coat. Sprinkle with 1/8 teaspoon salt. Bake on top rack of oven at 500° for 12 minutes or until beans are tender and beginning to brown, stirring once. Sprinkle with remaining 1/8 teaspoon salt and pepper.