Combine ingredients for Balsamic Vinaigrette in a jar or container with a tight fitting lid then shake to combine and set aside. Can be made up to 5 days ahead of time.
Add pasta to a large pot of salted, boiling water then cook until al dente. Drain then rinse under cold water until completely cool. Add pasta to a large mixing bowl with cherry tomatoes, mozzarella pearls, arugula, and basil, season with salt and pepper, then drizzle on desired amount of vinaigrette and toss to coat. If eating several hours after assembling, toss with more vinaigrette just prior to serving.
Notes
Since cooked gluten free pasta can harden when refrigerated overnight, this pasta salad is best eaten the same day it's made. Can be made then refrigerated for a few hours before your meal or event.