Preheat your oven’s broiler and line a baking sheet with foil. Place the poblano peppers on the sheet and roast, turning occasionally, until the skins are blackened and blistered (about 10-15 minutes). Transfer them to a plastic bag to steam for 10 minutes. Once cool, peel off the skins, cut off the stems, and scrape out the seeds.

Preheat your oven to 350°F. Lightly spray a 3-quart baking dish with nonstick spray. Arrange half of the roasted peppers in a single layer along the bottom of the dish.

Sprinkle half the shredded Monterey Jack cheese and cheddar cheese over the peppers. Create another layer with the remaining peppers, followed by the rest of the cheese. The cheesy layers are what make this casserole irresistibly gooey.

In a mixing bowl, whisk together the eggs, milk, flour, onion powder, garlic powder, baking powder, salt, and pepper. Make sure the mixture is free of any lumps, then pour it evenly over the cheese and peppers.

Bake the casserole in the preheated oven for about 45 minutes, or until the center is puffed and golden. Allow it to cool slightly for 5-10 minutes before cutting into squares. Garnish with sour cream, salsa, or fresh cilantro, then serve warm and enjoy!