Husk the corn and roast it in a skillet with a little olive oil over medium heat for 10–15 minutes, rotating every few minutes until lightly charred. Slice the kernels off the cob and set aside.
Bring a large pot of salted water to a boil. Cook the pasta until al dente according to package instructions. Drain and toss lightly with olive oil to prevent sticking.
Thinly slice the green onions and finely mince the shallot, garlic, jalapeños, and cilantro.
In a medium bowl, whisk together sour cream, mayonnaise, garlic, lime juice, lime zest, smoked paprika, chili powder, salt, and pepper to create the dressing.
In a large serving bowl, combine cooked pasta, roasted corn, green onions, shallot, jalapeños, cilantro, and cotija cheese.
Pour the dressing over the pasta salad and toss until everything is evenly coated.
Garnish with extra cotija cheese and fresh cilantro if desired. Serve chilled or at room temperature.