Bring a large pot of well-salted water to a boil. Cook the penne according to package directions until just al dente. Drain and spread the pasta out on a sheet pan or in a large bowl to cool slightly while you prepare the rest.

Heat 1 tablespoon of olive oil in a large skillet over medium-high heat until it shimmers. Add the zucchini in a single layer and season with salt and pepper. Cook without stirring for 2 to 3 minutes so the cut sides get golden and slightly caramelized. Flip and cook for another 2 minutes. The zucchini should be tender but not mushy. Transfer to a plate and let it cool for 5 minutes.

In a large mixing bowl, combine the halved cherry tomatoes, kalamata olives, sliced red onion, dried oregano, red wine vinegar, and the remaining 1 tablespoon of olive oil. Stir together so the onion and tomatoes start absorbing the vinegar.

Add the slightly cooled pasta and the sauteed zucchini to the bowl. Toss everything together gently until the pasta is coated. Taste and adjust salt, pepper, and vinegar to your liking.

Add the crumbled feta last and fold it in gently with a spoon or your hands so the chunks stay intact. Drizzle a little more olive oil over the top, scatter the parsley over everything, and serve warm or at room temperature.