For Sautéing the Onion and Garlic - Heat a medium-size sauce pan on medium heat and add butter. As the butter is melting add the onions and garlic, and stir. Let cook until the onions start to turn translucent. Remove the onions and garlic from the pan on to a plate or small bowl. Set aside.
For the Browned Butter - Heat the same pan on low to medium heat and add the butter. Continuously stir as the butter melts. Keep stirring until the butter starts to turn a golden color.
Then add the onions back to the pan. Add the tomato puree, red pepper flakes, pepper, salt, dried basil, vodka, and cream (or half and half).
Stir and let simmer for 10 minutes. Serve warm over pasta and top with grated Parmesan cheese.