Begin heating a large pot of water for the pasta. Once your water begins boiling, add a good spoonful of kosher salt and cook the pasta. Dip into the pasta water with a coffee cup and take out about a cup of water.
Heat the olive oil and the garlic in a large skillet over medium heat. Saute for 2 minutes, being careful not to burn or over brown the garlic. (A little golden is okay.) Add the tomatoes to the skillet, crushing the tomatoes in your hand as you add them. Bring the tomatoes to a simmer then reduce the heat to medium-low and cook them down for 10 minutes.
Add the pasta, 1/2 cup of the pasta water, the red pepper flakes, and parsley to the skillet with the tomato sauce. Increase the heat to medium-high and cook, stirring frequently and vigorously, until the sauce reduces and begins to coat the pasta, about 1 minute, adding more pasta water if needed. Keep cooking for a few moments more and you'll see the pasta and sauce become one. Add salt, pepper, and more red pepper flakes to taste.
Serve with grated parmesan and more parsley over the top.