01 - Boil a large pot of salted water. Add pasta and cook until al dente according to package directions. Drain, rinse with cold water to cool, and set aside.
02 - Heat a large skillet over medium-high heat. Add corn kernels and cook, stirring occasionally, until lightly charred in spots, about 5 to 6 minutes. Transfer to a bowl and let cool.
03 - In a large mixing bowl, whisk mayonnaise, sour cream, lime juice, chili powder, smoked paprika, garlic powder, cumin, salt, and black pepper until smooth and well blended.
04 - Add cooked pasta, charred corn, red bell pepper, green onions, cilantro, and jalapeño (if using) to the bowl. Toss thoroughly to coat all ingredients with dressing.
05 - Fold in crumbled cotija cheese gently, reserving a small amount for garnish.
06 - Taste and adjust salt or pepper as needed.
07 - Serve chilled or at room temperature, garnished with reserved cotija, extra cilantro, lime wedges, and a sprinkle of chili powder.