If using fresh corn, shuck the ears and carefully cut the kernels from the cob. Stand the corn upright in a large bowl to catch all the corn milk.
Heat olive oil or butter in a large skillet over medium-high heat. Add corn kernels and cook without stirring for 3-4 minutes until they begin to char slightly.
Stir the corn and continue cooking for another 3-4 minutes until tender with slight caramelization. Set aside to cool slightly.
In a large bowl, combine mayonnaise, Mexican crema, lime juice, garlic, chili powder, smoked paprika, and cayenne pepper. Whisk until smooth and well incorporated.
Add the cooked corn (cooled slightly), diced red onion, jalapeño, and cilantro to the dressing. Fold gently to coat all ingredients evenly.
Fold in most of the crumbled cotija cheese, saving a small amount for garnish. Season with salt and pepper to taste.
For best flavor, allow the salad to rest for 15-30 minutes before serving. Garnish with remaining cotija cheese and additional cilantro if desired.