Begin by roasting the red bell peppers. Place them under a broiler or on a grill, turning occasionally until the skin is charred and blistered (about 15 minutes). Once roasted, place them in a bowl and cover with plastic wrap to steam for about 10 minutes. Peel the skin, discard seeds, and chop the peppers.
In a large pot of salted boiling water, cook the penne pasta according to package instructions until al dente. Drain and set aside.
In a blender or food processor, combine the roasted red peppers, heavy cream, chopped basil, minced garlic, Parmesan cheese, and a pinch of salt and pepper. Blend until smooth and creamy.
In a large skillet over medium heat, add olive oil. Pour in the creamy red pepper mixture and let it simmer for about 5 minutes, stirring occasionally.
Once the sauce is warmed through, add the cooked penne pasta to the skillet and toss until all the pasta is well-coated with the sauce. If desired, add red pepper flakes for an extra kick.
Taste and adjust seasoning with additional salt and pepper as needed.
Serve hot, garnished with fresh basil leaves and a sprinkle of additional Parmesan cheese, if desired.