Heat the olive oil in a medium skillet over medium heat. Add the onion, bell pepper, parsley, garlic, jalapenos (if using), sugar and Italian seasoning. Cook, stirring frequently, until veggies are soft, about 4 to 5 minutes.
Add the cooked veggies to a crockpot, along with the tomato sauce, pasta sauce and meatballs. Cook on Low heat for 7 to 8 hours or High heat for 4 to 5 hours.
Serve over cooked spaghetti noodles and top with Parmesan cheese. Enjoy!