Add pasta to well salted (around 2 Tbsp. of salt) boiling water and follow the cooking the instructions on the pasta package to cook the noodles al dente (around 9 minutes or so). Make sure to save 1/2 cup of pasta water prior to straining your noodles as you will need that later.
While the pasta is cooking, heat the olive oil in a separate pan on medium heat.
Once the olive oil is hot, add the diced onion and cook until the onions are translucent (around 8 to 10 minutes). Reduce the heat if needed to keep the onions from browning.
Once the onion is cooked, add the minced garlic and cook until fragrant (around 30 seconds or so).
Then add the red pepper flakes, tomato paste, and vodka and stir together for around two to three minutes. Be careful when adding the vodka as the alcohol could cause it to flame up. If you don't like spicy food, you can leave the red pepper flakes out.
Next, add the can of peeled tomatoes to the sauce and cook for 10 minutes. While cooking, break apart the tomatoes as much as you can with a wooden spoon to incorporate them into the sauce.
After the tomatoes have simmered in the sauce for 10 minutes, reduce the heat to low and mix in the heavy whipping cream until it's combined into the sauce.
At this point, pour the sauce mixture into a blender or food processor and puree for 30 seconds or so until the onions and tomatoes are blended together and no chunks remain. Make sure your blender can handle hot liquids. If not, you can either use an immersion blender or allow the sauce to cool prior to blending.
Add the pureed sauce back into the pan. Then add the cooked pasta to the sauce along with 1/2 cup of the pasta water to finish. Stir the pasta into the sauce until the pasta is coated.
Turn off the heat and mix in the freshly grated parmesan cheese. Continue stirring until the cheese is melted and mixed into the sauce.
Garnish with fresh basil and enjoy!