This recipe for Bolognese freezes beautifully, so think about making a pot or two and freezing in appropriate containers for a quick dinner or snack at a later date.
Heat oil in a large skillet over medium-high. Add sausage, onion, bell pepper, and garlic, and cook, stirring, until sausage is browned and vegetables are tender, 8 to 10 minutes.
Stir in pasta sauce, sugar, salt, and black pepper; bring mixture to a boil over medium- high. Reduce heat to low; simmer 15 minutes.
Cook pasta according to package directions, reserving 1/2 cup cooking water. Stir chopped basil into meat sauce. Stir in up to 1/2 cup reserved cooking water, adding 1/4 cup at a time, if needed, to reach desired consistency. Serve sauce over cooked spaghetti. Garnish with shaved Parmesan cheese, if desired.