Put an oven rack in the center of the oven. Preheat the oven to 220°C. Butter an 8 by 8-inch glass baking dish. Set aside.
In a food processor, blend together the crushed tomatoes and garlic. Pour into a medium bowl and add the uncooked pasta, 1/3 cup olive oil, oregano, salt, and pepper. Toss until all the ingredients are coated.
Line the bottom and sides of the baking dish with tomato slices. Pour the pasta mixture into the pan and spread evenly. Arrange the remaining tomato slices in an overlapping layer on top of the pasta mixture, making sure the mixture is completely covered. Drizzle with olive oil. Bake until the tomatoes are slightly crispy and the pasta is cooked, about 1 hour. Remove from the oven and cool for 5 minutes before serving.