Preheat oven to 400 degrees.

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, turning to coat with oil.

Bake in the center of the preheated oven for 30 minutes.

Remove the baking dish, raise oven rack up to the upper third of the oven. Return baking dish to the oven and increase the 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, according to the time listed on pasta package.

Reserve 1/2 cup pasta water and right before draining, pour and submerge spinach in with the pasta. Drain pasta and spinach.

Smash the tomatoes, garlic, oil, and feta together with the back of a wooden spoon. Toss pasta in with this mixture along with basil, parsley, and red pepper flakes.

Thin the mixture with a few tablespoons of pasta water at a time to reach desired consistency. Season with salt and pepper as needed. Serve warm.