Pre-heat the oven to 200ºC.
Place the peppers, cut side down on a baking sheet, scatter on the tomatoes and garlic cloves. Give a good spray with low calorie cooking spray and season with a little salt. Place in the oven and cook for 20 minutes, until soft and the pepper is just beginning to char.
While the vegetables are roasting, cook the pasta in a pan of boiling salted water, according to packet instructions. Drain, reserving a little of the cooking water.
When the vegetables are cooked, place the pepper, garlic and half of the tomatoes into a blender along with the balsamic vinegar and 3 tbsp of the pasta cooking water.
Blitz to a smooth sauce. You can add a little more pasta water if it is too thick.
Put the sauce into the saucepan and put over a low heat to warm through.
Stir in the basil and the reserved tomatoes, then add the pasta to the pan and stir to coat well.
When warmed through, serve with a few fresh basil leaves for garnish.