Bring a large pot of salted water to a boil. Add the pasta and cook according to package directions until al dente. Drain the pasta and rinse it with cold water.

If using fresh corn, grill it over medium heat until lightly charred and cooked through, about 8-10 minutes, turning occasionally. Alternatively, you can boil the corn for 5-7 minutes, or sauté the kernels in a skillet with a little butter until tender and slightly browned. If using frozen corn, simply sauté it until heated through.

Once the corn is cool enough to handle, use a sharp knife to cut the kernels off the cob.

In a large bowl, whisk together the mayonnaise, sour cream, lime juice, chili powder, cumin, garlic powder, salt, and pepper until smooth and creamy. Taste and adjust the seasonings as needed.

Add the cooked pasta, corn kernels, cotija cheese, cilantro, red onion, and jalapeño (if using) to the bowl with the dressing. Gently toss everything together until well combined.

Cover the bowl and refrigerate for at least 30 minutes to allow the flavors to meld.

Before serving, give it another gentle toss and garnish with extra cotija cheese and cilantro, if desired.