Bring a large pot of salted water to a boil. Add pasta and cook until al dente according to package directions. Drain and rinse briefly under cool water to stop cooking. Transfer to a large mixing bowl and set aside.

Season chicken with salt, pepper, garlic powder, and paprika. Heat 2 tablespoons olive oil in a skillet over medium-high heat. Cook chicken 4–6 minutes per side until golden and cooked through (165°F internal). Let rest 5 minutes, then slice or cube.

Whisk together mayonnaise, Greek yogurt, lemon juice, Dijon mustard, Worcestershire sauce, minced garlic, and anchovy paste if using. Season with salt and pepper. Thin with a tablespoon of water or olive oil if desired.

Toss cooled pasta with most of the dressing until coated. Add chopped romaine, cherry tomatoes, and sliced chicken. Toss gently. Sprinkle with Parmesan and add croutons just before serving to maintain crunch.

Adjust seasoning with salt and pepper and serve immediately, or refrigerate (without croutons) for up to 3 days. Add croutons just before serving.