Spaghetti with Burst Cherry Tomatoes

Heat the oven to 400 degrees. Put the cherry tomatoes, 1 tablespoon of the olive oil, a big pinch of salt, and the sugar in a large bowl and toss to coat the tomatoes well. Line a rimmed baking sheet with a piece of parchment paper or aluminum foil. Pour the tomatoes onto the baking sheet, place them in the oven, and roast for 25 to 35 minutes, or until they collapse and their skins begin to char. Remove the tomatoes from the oven and let them cool slightly. Carefully lift the paper and pour the tomatoes and all their roasting juices back into the bowl.
Bring a large pot of water to a boil over high heat. Heat the remaining 1 tablespoon oil in a large skillet over medium heat. Add the garlic and red chile flakes and sauté for about 1 minute.
Add the roasted tomatoes with their juices and the oregano. Use a spoon to break up the tomatoes and cook until they are heated through. When the water is rolling, add a big pinch of salt, drop in the spaghetti, and stir. Cook the pasta according to the package instructions for al dente. Remove and reserve some of the pasta cooking water, then drain the pasta.
Add the pasta and about 1 tablespoon of the reserved cooking water to the tomato sauce. Stir and toss to thoroughly coat the spaghetti. Add a tablespoon or so of the remaining pasta water if the sauce is too dry or thick; drizzle with olive oil and season with salt and pepper to taste.
Turn the pasta into a serving bowl or individual bowls and pass the cheese, if using, at the table.