Cook pasta according to package instructions for al dente pasta. Rinse the pasta in cold water and drain well. Add the pasta to a large mixing bowl.
Add tomatoes, bacon, spinach, Mozzarella, and red onion to the pasta. Pour in 1/2 cup of the balsamic vinaigrette and toss to combine. Add more balsamic vinaigrette to make sure that all of the ingredients are well coated. Serve with additional balsamic vinaigrette on the side.