Place tomatoes, mushrooms, garlic cloves and blended cottage cheese into a 9x13” pan. Drizzle with olive oil. Sprinkle with black pepper, Italian seasoning, and optional crushed red pepper. Bake 30 minutes, until tomatoes burst. Stir.
Meanwhile, boil pasta in salted water until al dente. Drain and reserve 1/4 cup pasta water.
Add hot pasta and spinach to sauce and allow to sit 2-3 minutes before serving. If too thick, add pasta water, a tablespoon at a time.