Cook spaghetti according to package directions. Drain, rinse with cold water, and drain well. Place in large bowl.

In medium bowl, whisk salad dressing, cheese, seeds, salt paprika, garlic powder and peppers together until well blended. Stir in cucumber and onion. Pour over spaghetti and toss lightly to coat evenly. Cover and refrigerate at least 2 hours or up to 24 hours.

Garnish with tomatoes and parsley.