01 -  Bring a large pot of salted water to a boil. Add pasta and cook until al dente according to package instructions. Reserve 1/2 cup pasta water and drain. 
 02 -  While the pasta cooks, heat olive oil in a large skillet over medium heat. Cook onion for 2 to 3 minutes until softened, then add garlic and crushed red pepper flakes; sauté for 1 minute until fragrant. 
 03 -  Stir in crushed tomatoes, seasoning with salt and black pepper. Simmer uncovered for 5 minutes, stirring occasionally. 
 04 -  Pour in vodka. Cook for 2 to 3 minutes, allowing the alcohol to evaporate. 
 05 -  Reduce heat to low. Stir in heavy cream followed by Parmesan cheese. Simmer for 2 minutes, stirring until cheese has melted and sauce is smooth. 
 06 -  Add drained pasta into the skillet with sauce, tossing to coat. Use reserved pasta water as needed for desired consistency. 
 07 -  Plate pasta and top generously with torn basil leaves and more grated Parmesan. Serve immediately.