Preheat your grill to medium-high heat. Place the corn directly on the grill grates and cook, turning occasionally, until charred and cooked through, about 10 minutes. Remove from grill and let cool.
Once the corn is cool enough to handle, carefully cut the kernels off the cobs into a large mixing bowl.
Add the diced red bell pepper, chopped red onion, halved cherry tomatoes, and crumbled cotija cheese to the bowl with the corn.
In a small bowl, whisk together the mayonnaise, Greek yogurt, lime juice, chili powder, salt, and pepper until smooth. Adjust seasoning to taste.
Pour the dressing over the corn mixture and gently stir until everything is combined and evenly coated.
Fold in the chopped cilantro.
For the best flavor, cover and refrigerate for at least 30 minutes before serving to allow the flavors to meld.
Notes
Serve in a colorful bowl, garnished with extra cilantro and chili powder. Lime wedges can be served on the side.