In a small bowl, combine all dressing ingredients. Use hand whisk to incorporate well; try to get mayo mostly dissolved. Set aside (dressing can be made ahead of time and chilled until ready to use)
In a large skillet, heat olive oil over high heat. Once hot, add corn kernels and cook 3-5 minutes, stirring only occasionally. Once some of the kernels are nicely charred, turn off the heat. Add in parmesan, cilantro, bell pepper, green onions, red onion, jalapeño, and garlic powder, stirring well to combine. Toss with dressing and sprinkle with crumbled cojita (or feta) cheese. Serve at room temp or chilled.
Salad can be made a few hours ahead of time, covered, and chilled.