Preheat the oven: Set your oven to 375°F (190°C) and lightly grease a 9x13-inch casserole dish.
Make the base mix: In a large bowl, combine the shredded chicken, corn, green chilies, red bell pepper, green onions, cilantro, garlic powder, paprika, chili powder, salt, and pepper. Mix well until evenly distributed.
Prepare the creamy sauce: In a separate bowl, whisk together the mayonnaise, sour cream, lime juice, cumin, and both types of shredded cheese. Stir until smooth and creamy.
Combine: Pour the creamy mixture into the chicken and corn mixture. Stir thoroughly so everything is coated.
Assemble: Transfer the mixture into your prepared casserole dish. Spread it out evenly.
Add toppings: Sprinkle the top with crumbled cotija cheese and crushed tortilla chips if using.
Bake: Place in the oven and bake for 25–30 minutes, or until hot and bubbly around the edges and the top is lightly golden.
Garnish and serve: Remove from the oven, let cool for 5 minutes, then garnish with extra cilantro and serve with lime wedges.