Cook the pasta in salted boiling water until al dente, about 8 minutes. Drain and rinse under cold water until cool.

Whisk together the olive oil, balsamic vinegar, honey, Dijon mustard, garlic, salt, and pepper until smooth.

In a large bowl, combine the cooled pasta, cherry tomatoes, mozzarella, and red onion. Pour the dressing over and toss to coat.

Just before serving, fold in the basil, taste, and add more salt or pepper if needed. Serve cold or at room temperature.