Add grape tomatoes and garlic to a 3 quart baking dish. Toss with olive oil and a few pinches of salt and pepper. Place feta in the center of tomatoes, turn to coat with oil.
Bake in center of preheated oven for 30 minutes.
Then remove the baking dish, raise oven rack up to upper 1/3 of the oven. Return baking dish to oven and increase oven to 450 degrees. Bake until tomatoes and cheese are starting to brown slightly, about 10 minutes longer.
Meanwhile boil pasta to al dente in salted water (I use 1 Tbsp salt and about 3 or 4 quarts of water), according to time listed on pasta package.
Reserve 1/2 cup pasta water and right before draining pour and submerge spinach in with the pasta (it should wilt almost instantly). Drain pasta and spinach.
Smash the tomatoes, garlic, oil and feta together with the back of a wooden spoon. Toss pasta in with mixture along with basil, parsley and red pepper flakes.
Thin mixture with a few tablespoons of pasta water at a time to reach desired consistency. Season with salt and pepper as needed. Serve warm.