Thaw shrimp if necessary. Peel and devein, set aside until ready to use.
Saute chopped onion in 1 - 2 tablespoons of olive oil until soft. Add red pepper flakes, garlic, Italian Seasoning, and a little salt. Stir and cook for about 1 minute.
Add tomato sauce, diced tomatoes, and chicken broth. Simmer for about 5-7 minutes over medium low heat. Meanwhile, cook pasta. Once pasta is done, reserve about 1 cup of liquid before draining.
Add sugar to tomato sauce and stir well. Put in shrimp and cook 4-6 minutes*, stirring occasionally, until done. Add any of the reserved pasta water if you would like to thin the sauce any. You may not need to do this step. Stir in chopped basil, salt and pepper to taste.
Serve with your favorite pasta, top with Parmesan if desired.