Cook the pasta: Bring a large pot of salted water to a boil. Cook pasta according to package instructions until al dente. Reserve ½ cup pasta water, then drain.
Start the sauce: In a large skillet, heat olive oil and butter over medium heat. Add onion and sauté until soft and translucent, about 4 minutes. Stir in garlic and red pepper flakes; cook 1 minute until fragrant.
Add sundried tomatoes: Stir in chopped sundried tomatoes and cook for another 2 minutes to release their flavor.
Deglaze with vodka: Pour in the vodka, scraping the skillet to release any browned bits. Let it simmer for 2–3 minutes until the alcohol cooks off.
Build the creamy tomato base: Add crushed tomatoes and stir well. Simmer for 8–10 minutes, letting the sauce thicken.
Make it creamy: Lower heat and stir in heavy cream. Add Parmesan cheese and stir until smooth and creamy. Taste and adjust seasoning with salt and black pepper.
Combine pasta and sauce: Toss the cooked pasta into the sauce, adding a splash of reserved pasta water if needed for silkiness. Stir until pasta is fully coated.
Garnish and serve: Top with fresh basil and extra Parmesan before serving.