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 cooked pasta, sun-dried tomatoes, cherry tomatoes, spinach, feta cheese, black olives, and red onion.

In a small bowl, whisk together the olive oil, red wine vinegar, garlic powder, dried oregano, salt, and pepper.

Pour the dressing over the pasta salad and toss gently to combine all ingredients evenly.

Cover and refrigerate for at least 30 minutes to allow flavors to meld.

Serve chilled or at room temperature.