Cook the pasta according to package directions to al dente, adding ½ teaspoon of salt to the water. Drain pasta but reserve ½-1 cup of pasta cooking water before draining.

Add tomato paste. Stir the mixture until it's thoroughly combined and as Gigi recommends darker and a bit caramelized. Reduce the heat to low.

Slowly pour in the vodka, being careful if your stove has an open flame (remove the pan from the heat before adding). In Gigi’s original version she says you can make it with vodka (as penne alla vodka recipe) but this time she didn’t add any and says it was still gooood. Simmer until vodka is almost evaporated. About 2 to 3 minutes.

Pour in the heavy cream, and season with salt and black pepper, chili flakes. Stir to combine, then turn heat to a low simmer. Cook until creamy and starts to thicken but not yet complete. Add the parmesan cheese and stir until melts completely. The sauce should start to thicken, even more, it should coat the back of a wooden spoon.

Now add cooked pasta to the spicy tomato sauce and gently stir to coat. Top with butter. The sauce will be thick, you’ll need to add the reserved pasta cooking water to thin it out slightly. Add ½ cup of water or more to achieve the desired consistency. You’ll have to do it every time you reheat it (in case there are some leftovers!).

Serve right away with a side portion of green salad for a complete meal.