Bring a large pot of salted water to a boil, add the pasta, and cook for 8-10 minutes until al dente. Drain and rinse under cold water.

Heat a skillet over medium heat, add bacon slices, and cook for 5-7 minutes until golden brown. Drain excess grease and crumble the bacon.

In a mixing bowl, combine mayonnaise, sour cream, and buttermilk, whisk until smooth. Add garlic powder, onion powder, salt, and pepper; mix well.

In a serving bowl, combine the cooled pasta, crumbled bacon, cherry tomatoes, and red onion. Gently fold in cheddar cheese.

Pour dressing over the pasta mixture and toss for 1-2 minutes until everything is well coated.

Just before serving, gently mix in the chopped romaine lettuce.