1. Preheat oven to 400°.
2. Arrange asparagus in a single layer on baking sheet; coat with cooking spray. Sprinkle with salt and pepper. Bake at 400° for 12 minutes or until tender.
3. Melt the butter in a small skillet over medium heat; cook for 3 minutes or until lightly browned, shaking pan occasionally. Remove from heat; stir in soy sauce and vinegar. Drizzle over asparagus, tossing well to coat. Serve immediately.