Cook the pasta: Bring a large pot of salted water to a boil. Cook the pasta until just al dente, according to package directions.
Drain and rinse under cold water to stop the cooking and cool it down.
Make the dressing: In a large mixing bowl, whisk together the buffalo sauce, ranch or blue cheese dressing, and Greek yogurt or sour cream. Add lemon juice, garlic powder, onion powder, a pinch of salt, and a few grinds of pepper. Taste and adjust seasoning.
Prep the mix-ins: Chop the chicken, celery, carrot, and red onion.
If using cheese or herbs, crumble or chop them now.
Combine: Add the cooled pasta to the bowl with the dressing. Toss to coat. Fold in the chicken, celery, carrot, red onion, and herbs.
Add cheese if using.
Adjust consistency: If it looks dry, add a splash more buffalo sauce or a spoonful of dressing. If it’s too spicy, stir in more yogurt or ranch to mellow it out.
Chill: Cover and refrigerate for at least 30 minutes. This helps the flavors meld and the dressing cling to the pasta.
Finish and serve: Stir the salad before serving.
Garnish with extra herbs and a little drizzle of buffalo sauce if you like. Serve cold or at cool room temperature.