Char the corn: Heat a dry cast-iron skillet over medium-high heat. Add the thawed corn kernels and spread them in a single layer. Cook without stirring for 3-4 minutes, until kernels begin to blacken and char slightly. Stir occasionally for another 3-4 minutes until lightly browned. Remove from heat and set aside.

Preheat the oven to 375°F (190°C). Lightly grease an 8x8 inch baking dish.

Combine wet ingredients: In a large mixing bowl, combine the softened cream cheese, mayonnaise, sour cream, lime juice, smoked paprika, chili powder, and cumin. Mix well until smooth and fully incorporated.

Mix in solids: Fold in the charred corn, Monterey Jack cheese, three-quarters of the crumbled cotija cheese (reserving the rest for topping), and the chopped cilantro. Mix until everything is evenly distributed. Taste and adjust seasoning with salt and pepper.

Bake the dip: Transfer the mixture to the prepared baking dish. Top evenly with the remaining reserved cotija cheese.

Bake for 15-20 minutes, or until the dip is hot and bubbly throughout and the top cheese is lightly golden.

Garnish and serve: Remove from the oven, sprinkle with reserved lime zest and a dusting of chili powder. Serve hot with tortilla chips, sturdy crackers, or vegetable sticks.