Preheat the oven to 400 degrees.
Wash tomatoes and remove the stems. Place in a baking dish.
Drizzle the olive oil on the tomatoes, season with salt and pepper to taste.
Place the feta in the center.
Bake for 35 minutes. While the tomatoes are roasting, cook the spaghetti according to the directions on the box.
Remove the tomatoes from the oven and use a potato masher to crush tomatoes.
Stir the feta cheese and tomatoes together.
Use tongs to mix the spaghetti into the sauce.
Serve.