Step 1

Bring a large pot of water to a boil and add a generous amount of salt. Add the pasta and cook until al dente according to the package directions. Reserve about 1 cup of the pasta water, then drain the pasta and set aside.

Step 2

Meanwhile, heat the oil and 1 tablespoon of the butter in a large saute pan over medium heat. When the butter is melted, add the garlic, celery, shallots and onions, reduce the heat to low and cook until the onions are translucent, 6 to 8 minutes. Season with salt and pepper.

Step 3

Add the vodka, raise the heat to medium high and cook until the vodka is almost evaporated, about 2 minutes. Mix in the tomato paste. Add the cream, sugar and red pepper flakes, if using, and season again with salt and pepper. Reduce the heat to medium low and let the sauce simmer gently so the flavors come together, about 5 minutes. Taste the sauce and season again, if needed.

Step 4

Add the pasta to the sauce and mix to combine; add some pasta water if it seems dry. Add the remaining 2 tablespoons butter and mix to combine and melt the butter. Remove from the heat, add the Grana Padano and parsley and mix gently to combine. Transfer to serving bowls and finish with some more Grana Padano, freshly ground black pepper and a sprinkle of parsley.