01 - Cook pasta in a large pot of salted boiling water according to package directions until al dente. Drain and rinse under cold water to stop cooking. Set aside.
02 - Grill corn on a preheated grill or grill pan, turning occasionally, until lightly charred on all sides, about 8–10 minutes. Allow to cool, then slice kernels from cobs. For frozen corn, sauté in a dry skillet over medium-high heat until lightly charred.
03 - In a large mixing bowl, whisk together mayonnaise, sour cream, lime juice, chili powder, smoked paprika, ground cumin, salt, and black pepper until smooth.
04 - Add cooked pasta, charred corn, diced red bell pepper, sliced green onions, chopped cilantro, crumbled Cotija cheese, and diced jalapeño if using into the bowl. Toss gently until evenly coated with dressing.
05 - Taste and adjust seasoning as desired. Refrigerate for at least 30 minutes prior to serving to enhance flavors.