Cook the pasta: Bring a large pot of salted water to a boil. Cook the high-protein pasta according to package directions until al dente.
Reserve 1/2 cup of the starchy water, then drain.
Season the chicken: Pat the chicken dry. Toss with garlic powder, onion powder, smoked paprika, salt, and pepper.
Sear the chicken: Heat olive oil in a large nonstick skillet over medium-high. Add chicken in a single layer and cook 5–7 minutes, stirring occasionally, until cooked through and lightly browned.
Build the sauce base: Lower heat to medium.
Stir in buffalo sauce and broth (or reserved pasta water). Simmer 1–2 minutes so the flavors meld.
Add creaminess: Reduce heat to low. Stir in softened cream cheese until smooth.
Remove the pan from heat and whisk in Greek yogurt and ranch seasoning. Keep it off direct heat to prevent curdling.
Combine with pasta: Add drained pasta to the skillet and toss until every piece is coated. If it looks thick, loosen with a splash of reserved pasta water.
Finish and taste: Stir in Parmesan (if using) and half the green onions.
Taste and adjust salt, pepper, and buffalo sauce.
Serve: Top with remaining green onions. Add blue cheese crumbles or herbs if you like. Serve hot.