Begin by bringing a large pot of salted water to a rolling boil over high heat. Once boiling, add the spaghetti and cook according to the package instructions until al dente, about 8–10 minutes.

After the spaghetti is cooked, drain it in a colander and rinse under cold running water to cool quickly.

Chop the vegetables: halve the cherry tomatoes, dice the cucumber, finely chop the green and red bell peppers, and red onion. Slice black olives into rounds.

In a large mixing bowl, add the cooled spaghetti and chopped vegetables. Gently toss together.

Drizzle the Italian dressing over the mixture and toss until evenly coated.

Season with salt and pepper to taste, and add grated Parmesan cheese if desired.

Transfer the salad to the refrigerator and let it chill for at least one hour for the best flavor.