Heat butter or olive oil in a large skillet over medium-high heat. Add corn kernels and cook for 5-7 minutes, stirring occasionally, until corn is tender and slightly charred.
Remove the skillet from heat and let the corn cool for a few minutes.
In a large bowl, combine mayonnaise, sour cream or crema, cotija cheese, lime juice, chili powder, and smoked paprika. Stir until well combined and smooth.
Add the cooked corn, chopped cilantro, and minced jalapeño to the dressing mixture. Stir gently to coat all the corn.
Taste and season with salt and freshly ground black pepper as needed.
Transfer the salad to a serving bowl. Garnish with additional cotija cheese, a sprinkle of chili powder, and extra cilantro before serving.
Serve immediately as a side dish or chill for at least 30 minutes for flavors to meld.