Bring a large pot of salted water to a rapid boil. Add pasta and cook until al dente, approximately 8-10 minutes. Drain and cool to room temperature.

Preheat your oven to 400°F (200°C). Line a baking sheet with foil and lay out bacon in a single layer. Bake for about 25 minutes until crispy. Cool slightly and chop.

In a medium bowl, combine sour cream and ranch dressing. Whisk until smooth and creamy. Set aside.

In a large mixing bowl, combine cooled pasta, green onions, cheddar cheese, and half the bacon. Toss gently.

Pour the dressing over the pasta mixture and fold until well-coated. Cover and refrigerate for at least 30 minutes.

Before serving, stir the salad gently, sprinkle remaining bacon on top, and garnish with more green onions. Serve chilled or at room temperature.