Cook penne according to instructions on package. Reserve one cup of pasta cooking liquid to adjust consistency of your sauce, if necessary.
In a large pot or a deep saucepan, add the rosa sauce and bring to a low simmer.
Carefully add your preferred amount of cooked pasta along with a generous spoonful of butter (optional) and toss or stir to coat your noodles and fill them with sauce.
Continue cooking over medium-low heat — add pasta water or additional sauce to make sure the pasta sauce doesn’t get too thick. It should have the consistency of slightly reduced cream.
Season with salt and chili flakes to taste, and garnish with a liberal amount of grated Grana Padano.