Chef John's Vodka Sauce Penne

Heat olive oil in a substantial, deep pan over medium heat and cook the pancetta along with a fragrant rosemary sprig until the fat is released but the pancetta remains soft, approximately 5 minutes. Carefully pour vodka into the pan while maintaining a safe distance to avoid any sudden flames. Increase the heat to high and continue cooking until the vodka has almost completely evaporated, leaving about 2 tablespoons behind.

Add a generous amount of heavy cream to the pan, stir it briefly, and sprinkle some black pepper over the top; bring the sauce to a rolling boil. Lower the heat to medium and cook, stirring occasionally, until the sauce has slightly thickened, about 3 to 4 minutes. Combine marinara sauce and water in the cream mixture and bring it to a gentle simmer. Reduce the heat even further and let the sauce cook for 20 to 25 minutes, allowing the flavors to meld together.

Fill a large container with salted water and bring it to a boil. Gently stir in penne pasta and return the water to a rolling boil. Cook the pasta, stirring occasionally, until it's cooked through but still retains some firmness, approximately 10 minutes; drain and return the pasta to the container. Pour the prepared sauce over the penne, stirring it in thoroughly. Turn off the heat and cover the container with a lid; let the pasta sit for 5 minutes, allowing it to absorb the flavors of the sauce. Serve the penne pasta sprinkled with Parmesan cheese.