- Preheat oven to 400 degrees. Arrange asparagus spears in a 9x13-inch baking dish (or similar). Coat the top of asparagus with cooking spray, then season with salt and pepper to taste.
- Bake asparagus until tender (about 10 minutes depending on thickness of spears).
- Melt butter in a small, nonstick saucepan over medium heat, then remove pan from heat. Stir in the soy sauce and vinegar to make a sauce. Pour the sauce over the baked asparagus spears and serve.