Heat 1 tablespoon olive oil in a large skillet over medium-high heat.
Add the corn in an even layer, then leave it alone for 2 minutes.
Stir and cook 6 to 8 minutes, until browned in spots.
Move the corn to a large bowl and cool it for 5 minutes.
Whisk mayonnaise, sour cream, lime juice, lime zest, garlic, chili powder, smoked paprika, cumin, kosher salt, and black pepper.
Add the dressing to the warm corn, then stir gently.
Fold in cotija, cilantro, red onion, and jalapeño.
Taste, then add more lime, salt, or chili powder if needed.
Sprinkle extra cotija and chili powder on top before serving.