Place a large cast-iron skillet over high heat and add butter.
Once the butter is melted and shimmering, add the corn kernels in a single layer.
Allow the corn to char undisturbed for 3 minutes, then stir and cook for an additional 2-3 minutes until toasted.
In a separate large mixing bowl, whisk together mayonnaise, Mexican crema, lime juice, garlic, chili powder, and smoked paprika.
Incorporate the charred corn into the dressing bowl while still warm.
Fold in the minced jalapeño, chopped cilantro, and crumbled Cotija cheese.
Season with salt and adjust acidity with extra lime juice if necessary.
Serve immediately or refrigerate for up to 2 hours.