Heat the oil over medium-high heat in a large skillet. Sauté the garlic for 30 seconds, then add the red pepper flakes and Italian seasoning and toast the spices for another 30 seconds.
Add the crushed Italian tomatoes, sugar, salt, and pepper, and stir to combine. Bring the sauce to a low simmering boil, then reduce the heat to low, cover, and let it simmer for 20 minutes.
Cook the pasta
Cook the pasta according to the package directions. Before draining, reserve 1 cup of the pasta water and set it aside. Drain the pasta.
Combine
Combine the pasta with the sauce and ½ cup of the reserved pasta water. Toss to combine well, turn off the heat.