Fill a large pot with water and 1 tbsp of salt and boil your pasta according to the package directions.
While the pasta is cooking, slice your tomatoes into 1/4 inch slices and cut your mozzarella into 1/2 inch cubes. These sizes are just my preference so if you like them smaller or bigger, go for it!
Once your pasta is done, drain it and rinse it with cold water. You do NOT want your mozzarella to get melty.
Add your cooled pasta to a mixing bowl along with the tomatoes, mozzarella, pesto, balsamic, olive oil, salt, pepper, and garlic powder.
Toss together and either serve at room temperature or refrigerated.