Add the olive oil, vinegar, lemon juice, Dijon, honey, garlic, oregano, salt, pepper, onion powder, thyme, crushed red pepper, and parmesan to a jar or small bowl. Whisk or shake until well combined.
Boil the rotini in generously salted water until it is just al dente. Drain it, rinse it under cold water, and let it cool completely. Toss with the olive oil so the pasta does not stick together.
Chop the tomatoes, peppers, onion, cucumber, and parsley into small, bite-size pieces. Add them to a large bowl with the pasta, feta, and pepperoncini.
Combine everything:
Pour the dressing over the salad and toss until every piece is coated.
Chill before serving:
Cover the bowl and refrigerate for at least 30 minutes so the flavors can mingle. Give it one more toss before serving.