Bring a large pot of salted water to a rolling boil. Add the rotini pasta and cook according to package directions until al dente, usually 8-10 minutes.
Drain the pasta in a colander and immediately rinse under cold running water until completely cooled. Shake off excess water.
Transfer the cooled pasta to a large mixing bowl. If pasta seems sticky, toss with a small drizzle of olive oil.
Add the diced ham, halved cherry tomatoes, diced cucumber, and sliced red onion to the bowl with the pasta.
Sprinkle the shredded cheddar cheese over the mixture.
Add the chopped fresh basil and gently toss to distribute evenly throughout the salad.
Pour the Italian vinaigrette over the salad ingredients, starting with about ΒΌ cup and adding more as needed.
Gently toss all ingredients together until everything is evenly distributed and coated with dressing.
Season with salt and freshly ground black pepper to taste.
Cover the bowl and refrigerate for at least 30 minutes, though 1-2 hours is ideal for flavor development.
Before serving, give the salad another gentle toss and taste again for seasoning, adding more salt, pepper, or dressing if needed.
