Bring a large pot of water to boil.

Heat the 2 tablespoons of the olive oil in a heavy bottom skillet over medium high heat.

Add the mushrooms and saute for about 10 minutes, stirring occasionally, until the mushrooms are golden brown and caramelized. If you're adding spinach, add the spinach and wilt it down. Taste and season with salt and pepper as needed.

In a blender or food processor, combine the roasted red bell peppers, garlic, salt, pepper, remaining 2 tablespoons olive oil and vinegar. Blend for 1-2 minutes until the ingredients become smooth. Taste and adjust seasonings as needed. Add the sauce to the pan with the mushrooms and stir to combine.

Add the pasta to the boiling water and cook according to the package directions. Once the pasta is cooked, reserve ½ cup of the pasta water and drain the pasta. Add the cooked pasta to the mushroom mixture and toss to combine. Add the reserved water if you need to thin out the sauce. Adjust salt and pepper if needed and serve and serve with freshly shredded parmesan cheese and basil leaves.