1. With the spinach added, It is cooked for about 5 to 8 more minutes and then removed from the heat. The pasta will be cooked but still firm when you bite into it. I leave it covered in the pot on the kitchen counter and as it absorbs the sauce it continues to soften. Just follow the instructions for the cooking time on the box and follow it in this recipe. Although in this recipe you are not going to be boiling the pasta separately in water as most instructions on boxes suggest, so just use this as a guide on how long to cook it with the sauce.