Cook the pasta:
Bring a large pot of salted water to a boil. Cook the pasta according to the package instructions until al dente. Drain and rinse with cold water to cool. Set aside.
Prepare the ground beef:
In a skillet over medium heat, cook the ground beef until browned and fully cooked. Drain excess grease and stir in the taco seasoning with ¼ cup of water. Simmer for 2–3 minutes. Remove from heat and allow to cool slightly.
Make the dressing:
In a small bowl, whisk together the sour cream, mayonnaise, lime juice, chili powder, cumin, garlic powder, salt, and pepper. Adjust seasoning to taste.
Assemble the salad:
In a large mixing bowl, combine the cooked pasta, seasoned ground beef, cherry tomatoes, black beans, corn, shredded cheese, red onion, and lettuce. Gently fold in the dressing until everything is evenly coated.
Add toppings:
Just before serving, gently mix in the avocado and top with crushed tortilla chips, cilantro, and diced jalapeños, if desired.