Bring a large pot of salted water to a boil and cook the pasta until al dente. Drain and let it cool while you prep the rest.

If using fresh corn, brush the corn with butter and grill (or pan-sear in a skillet with butter) until lightly charred, about 8–10 minutes. Slice the kernels off the cob once cool enough to handle. If using frozen corn, add butter to skillet and heat over medium heat. Cook until warmed, about 8 minutes, stirring often.

In a bowl, whisk together the mayo, sour cream or Mexican crema, lime juice, chili powder, cumin, salt, and pepper until smooth. For extra spice and smoky flavor, add chopped canned chipotle chilies in adobo.

In a large bowl, combine the pasta, corn kernels, red onion, jalapeno, cilantro, and Cotija cheese. Pour the dressing over and toss to coat evenly.

Cover and chill the salad for at least 30 minutes to let the flavors meld. Just before serving, top with extra cotija cheese, a squeeze of lime, cilantro, and a sprinkle of chili powder.