Preheat your oven to 350°F (175°C) and lightly coat a 9x13-inch baking dish with non-stick spray or a thin layer of oil.
Place half of the prepared green chiles evenly along the base of the baking dish. Distribute half of each type of shredded cheese over the chiles. Layer the remaining chiles on top, followed by the rest of the cheese.
In a mixing bowl, combine the eggs, milk, heavy cream, flour, baking powder, garlic powder, onion powder, salt, and black pepper. Whisk the mixture until it becomes smooth and well-blended.
Carefully pour the egg mixture over the layers in the baking dish, ensuring even coverage. Transfer to the oven and bake uncovered for 35 to 40 minutes, until the surface is golden and the center is fully set.
Remove the casserole from the oven and gently pour the enchilada sauce across the top. Return the dish to the oven and bake for an additional 5 minutes.
Allow the casserole to sit at room temperature for about 5 minutes before slicing. Garnish with freshly chopped cilantro if desired.