Begin by boiling a large pot of salted water. Once it reaches a rolling boil, add rotini pasta and cook until al dente, about 8-10 minutes. Drain and rinse under cold water.

In a large skillet over medium heat, add chopped bacon and cook for about 8-10 minutes until crispy. Transfer to a paper towel-lined plate to cool.

In a mixing bowl, combine mayonnaise, sour cream, and a splash of milk to reach your desired consistency. Mix until creamy.

In a large serving bowl, add the cooled rotini pasta, chopped bacon, and diced fresh tomatoes. Pour the dressing over and toss gently until everything is well coated.

Just before serving, fold in the chopped lettuce to preserve its crispness.

Cover and refrigerate for at least 15 minutes before serving to allow flavors to meld.