Put the corn and 2 tablespoons olive oil on a baking sheet. Sprinkle with salt and pepper and toss to combine. Roast, stirring halfway through, until slightly darkened in color, 15 to 20 minutes.
Remove the pan from the oven and add the onion, bell pepper, jalapeno, garlic, cumin, chili powder, remaining 2 tablespoons olive oil and some salt and pepper and toss to combine with the corn. Continue roasting for another 12 to 15 minutes.
Remove the pan from the oven and add the mayonnaise, lime juice, cilantro and cheese, stirring to combine. Transfer to a serving bowl and top with more cilantro, shredded cheese and chili powder. Serve with tortilla chips.