Bring a large pot of water to a boil, then add about a tablespoon of salt. Cook the pasta until al dente, reserving 1/2 cup of the starchy pasta water before draining the pasta.
12 ounces penne pasta
Meanwhile, make the vodka sauce by heating a large skillet over medium-high heat. Add the olive oil and butter and heat until the butter is melted. Add the onion and sauté until softened, about 5 minutes. Add the garlic in the last 30 seconds.
2 Tablespoons olive oil, 2 Tablespoons salted butter, 1 medium sweet yellow onion, 4 cloves garlic
Add the vodka to the cooked onions and let it cook down until almost completely evaporated, about 30-60 seconds. Stir in the tomato paste, crushed red pepper flakes, oregano, salt, and pepper.
1 Tablespoon tomato paste, 1/2 teaspoon crushed red pepper flakes, 1/2 teaspoon oregano, 1/2 teaspoon kosher salt, 1/2 cup vodka, 1/4 teaspoon freshly ground black pepper
Add the crushed tomatoes, then reduce the heat to medium-low and simmer for 15 minutes to thicken slightly.
28 ounces crushed tomatoes
Add the cream and stir until warmed through.
3/4 cup heavy cream
Add the drained pasta to the sauce, tossing to coat. Add a splash or two of the reserved pasta water, up to the full 1/2 cup to get the sauce just the consistency you like.
1/2 cup reserved pasta water
Serve the pasta sprinkled with freshly grated Parmesan and thinly sliced basil.
1/4 cup freshly grated Parmesan for serving, 1/4 cup fresh basil