Preheat oven to 400°F. Line a baking sheet with foil.
Slice tomatoes into quarters and place onto the baking sheet. Add fresh basil, drizzle with olive oil, and season with salt and pepper.
Wrap garlic in foil and place on baking sheet with the tomatoes. Toss in the preheated oven and roast for 40-45 minutes.
Meanwhile, cook pasta as directed on package.
Once the tomato skins begin to shrivel, remove from the oven. Allow to cool slightly, then add to a high-powered blender or food processor. Blend until desired texture is reached.
Serve spaghetti topped with freshly made sauce; serve with oranges on the side.