Creating the delicious Street Corn Pasta Salad is straightforward. Follow these steps:

1. Cook the Pasta: Bring a large pot of salted water to a boil. Add the pasta and cook according to package instructions until al dente. Drain and rinse under cold water to cool.
2. Prepare the Corn: If using fresh corn, grill or roast the corn until slightly charred. Allow it to cool, then cut the kernels off the cob.
3. Mix the Dressing: In a large bowl, whisk together the lime juice, mayonnaise, sour cream, chili powder, salt, and pepper until smooth.
4. Combine Ingredients: In a large mixing bowl, combine the cooked pasta, corn, cherry tomatoes, red onion, cilantro, and avocado.
5. Add Dressing: Pour the dressing over the pasta mixture and gently toss until everything is evenly coated.
6. Add Cheese: Sprinkle the cotija cheese over the salad and fold it in gently.
7. Chill: Cover the salad and refrigerate for at least 30 minutes to allow the flavors to meld.
8. Adjust Seasoning: Before serving, taste and adjust seasoning if necessary.
9. Serve: Transfer the salad to a serving bowl and garnish with additional cilantro or cheese if desired.

These clear steps will lead you to a beautifully delicious Street Corn Pasta Salad.