Cook the rotini pasta according to package instructions until al dente. Drain and rinse under cold water to cool.
In a large bowl, combine the cooled pasta, cherry tomatoes, cucumber, red onion, olives, feta cheese, and parsley.
In a small bowl, whisk together the olive oil, red wine vinegar, oregano, garlic powder, salt, and pepper.
Pour the dressing over the pasta salad and toss gently to combine.
Cover and refrigerate for at least 30 minutes to allow the flavors to meld. Serve chilled or at room temperature.