Bring a large pot of salted water to a rolling boil.
While the pasta cools, dice the ham into bite-sized cubes, finely chop the bell peppers, red onion, and celery, and drain the pineapple chunks thoroughly to avoid excess liquid in the salad.
In a mixing bowl, whisk together mayonnaise, Greek yogurt, Dijon mustard, lemon juice, garlic powder, salt, and pepper until smooth and well combined.
In a large salad bowl, toss together the cooled pasta, diced ham, pineapple chunks, bell peppers, red onion, celery, and shredded cheddar cheese. Mix gently so that everything is evenly distributed.
Pour the dressing over the salad and toss gently to coat every piece with that luscious, creamy goodness. Be careful not to overmix—just enough to ensure every bite is packed with flavor.