Melt butter in a cast iron pan over medium/high heat.
Spread corn kernels in a single layer in the pan. Pan fry 5-10 minutes, stirring frequently, until the outsides of the kernels have browned. (Some will have a charred look, but don't let them burn).
Transfer corn to large bowl.
Add mayonnaise, crumbled cheese, cilantro, lime juice, chili powder. Add salt to taste. Stir until combined.
Divide the elote mixture into individual plastic cups.
Sprinkle with extra crumbled cheese, chili powder, and cilantro.
Serve warm immediately.