Heat a Dutch oven or medium pot over medium-high heat. Add olive oil and swirl to coat bottom of pan. Add sausage and stir occasionally until sausage is browned. Transfer sausage to a medium bowl and set aside.
Saute shallot in remaining pan drippings over medium-high heat. Add garlic and red pepper flakes to pot and saute 1 additional minute until fragrant. Deglaze pan with vodka, scraping up any browned bits.
Add tomato paste, whole tomatoes, half of roasted red peppers, and basil leaves to pot. Bring sauce to a simmer over medium-high heat, then reduce heat to medium-low, cover, and let simmer 20-30 minutes until slightly reduced.
Discard basil leaves, transfer sauce to a blender and blend on high speed until sauce is smooth. Pour sauce back into pot and stir in heavy cream, sausage, remaining roasted red peppers, and penne.
Season penne with salt and pepper to taste. Serve penne alla vodka warm with fresh basil and Parmesan on top and enjoy!