Prepare the roasted garlic by preheating the oven to 205 degrees celcius. Put some garlic cloves into an aluminium foil, and drizzle with olive oil and season with salt and pepper. Wrap it up and bake it for 30 minutes, then let it cool and squeeze out the roasted garlic

Bring the water up to a boil in a pot, and season heavily with salt. Once the water has reached a boil, add the pasta, and set a timer for 1-2 minutes less than what the package says, make sure to stir the pasta a few times in the first few minutes to avoid sticking

Pour the olive oil in a large skillet and heat it over medium heat. Add the pepper flakes, roasted garlic and chopped garlic, sauteing it and stirring constantly for about 45 seconds. Be careful not to burn the ingredients, then turn off the heat, add the butter and set the sauce aside

When the pasta is done, leave some pasta water to emulsify the sauce, and drain the pasta. Then set the sauce over medium low heat again, and add in the pasta with a quarter of the pasta water saved earlier. Stir vigourously until the sauce comes together and begins to coat the spaghetti, and add extra pasta water if necessary. Stir in the parsley, and season it with salt and pepper and serve right away