1. Preheat oven to 425 degrees Fahrenheit. Grease a baking sheet with nonstick cooking spray.
2. Place tomatoes in baking pan, cut side up. Sprinkle with salt.
3. In a bowl, combine cornflake crumbs, olive oil, garlic powder, salt, and pepper. Sprinkle the mixture over the tomatoes. Bake for eight to 10 minutes.
4. Remove from oven. Sprinkle with shredded cheese. Return to oven. Bake for an additional five minutes.