In a saucepan over medium-high heat, add butter and olive oil.
Add the diced onions and sweat for 5 minutes until softened.
Reduce the heat and add the minced garlic and crushed red pepper flakes.
Stir in the tomato puree, vodka (if using), salt, sugar, torn basil, and oregano.
Bring the sauce to a simmer, then cover and reduce heat to low. Let it cook for 30 minutes.
Taste and adjust salt as needed.
Once ready to serve, add the reserved pasta water to the marinara sauce.
Stir in the ricotta cheese, Parmesan cheese, and cooked penne pasta.
Add 1-2 tablespoons of balsamic vinegar and stir until the pasta is thoroughly coated in the sauce.
Adjust with more balsamic vinegar, salt, or crushed red pepper flakes to taste, if desired.