Melt the butter in a large skillet over medium-high heat until fully melted and bubbling.
Add the dried corn in a single even layer. Do not stir.
Let the corn sit untouched for 7–9 minutes, until a good portion of the kernels are deeply golden-brown.
Stir once, scraping up any browned bits from the bottom of the pan.
Add the diced jalapeño and cook for 1–2 minutes, until slightly softened.
Remove the pan from the heat completely.
Stir in the mayonnaise and sour cream until every kernel is coated.
Fold in the cotija cheese, lime juice, cilantro, chili powder, and smoked paprika.
Taste and adjust salt and pepper as needed.
Transfer to a serving bowl and serve warm.