Boil a large pot of salted water, add pasta, and cook according to package directions until al dente, about 8-10 minutes. Reserve a cup of pasta water before draining.

Heat olive oil in a skillet over medium heat, season chicken with salt and pepper, and cook for about 5-7 minutes until golden brown. Shred the chicken.

Combine buffalo sauce and ranch dressing in the skillet or mixing bowl. Stir until smooth.

Add reserved cooked pasta and shredded chicken to the skillet, tossing gently to coat. Adjust consistency with reserved pasta water if needed.

Sprinkle shredded cheddar cheese and diced green onions over the pasta mixture, stir gently, and let the heat melt the cheese.

Spoon the pasta into bowls and garnish with extra green onions or buffalo sauce if desired.