To get started, make the pasta. Heat a large pot of water to boiling, add the pasta noodles, and cook them according to the package instructions.
Be sure to reserve 1 cup of cooked pasta water before draining and rinsing the noodles. Set the cooked noodles aside until adding them to the sauce.
Using a large skillet, heat up the olive oil in the skillet over medium heat.
Add in the garlic and shallot and cook that for 3-5 minutes, or until soft.
Next, add the vodka and deglaze the pan. Add in the tomato paste, cream, salt, pepper, and red pepper flakes. Cook these ingredients together until they are heated through, or 5-8 minutes.
At this point, you may need to add a little of the reserved pasta water to the sauce. Add one tablespoon of water at a time until you reach your desired consistency of the sauce.
Finally, pour in the cooked penne noodles and butter. Mix everything together until the butter is melted and the noodles are coated with the vodka sauce.
Garnish with parmesan cheese and fresh parsley. Serve warm.