Bring a large pot of water to a boil and cook pasta shells according to package directions; stir occasionally to prevent sticking. Drain and rinse under cold water until cool to the touch, then drain well.

Heat a large skillet over medium-high heat and brown the ground beef until no longer pink, breaking it up as it cooks. Add taco seasoning, then cook according to the packet directions (typically 1-2 minutes) until the mixture is evenly coated.

In a mixing bowl, whisk ranch dressing with salsa until smooth and evenly colored.

In a large bowl, combine the cooled pasta, taco-seasoned beef, shredded cheddar, cherry tomatoes, corn, black beans, and diced red onion.

Pour the ranch-salsa dressing over the salad and toss thoroughly to coat all ingredients.

Cover and refrigerate for at least 2 hours so the flavors meld and the salad thickens slightly as it chills.

Before serving, top with crushed Doritos and add lettuce, sour cream, and cilantro.