Directions

1. In a large pot of boiling salted water, cook pasta according to package instructions; reserve 1 cup water and drain well.
2. Heat 2 tablespoons olive oil in a large cast iron skillet over medium heat. Add breadcrumbs and cook, stirring, until browned and toasted, about 3-5 minutes; season with salt and pepper, to taste. Set aside.
3. Heat remaining 4 tablespoons olive oil in the skillet. Add garlic and red pepper flakes, and cook, stirring frequently, until garlic is golden, about 2-3 minutes.
4. Add pasta, 3/4 cup Parmesan and 1/2 cup reserved pasta water. Cook, stirring constantly, and add remaining water as needed, 1 tablespoon at a time, until cheese has melted and desired consistency is reached.
5. Serve immediately with breadcrumbs, garnished with remaining Parmesan and parsley, if desired.