Set oven rack under broiler and broil poblano peppers on a foil-lined baking sheet for 5 minutes per side until skin is blackened and blistered.

Remove baking sheet and loosely cover with foil or plastic wrap to steam the peppers for 5 minutes, allowing the skin to soften.

Peel off and discard as much of the loose skin from each pepper as possible.

Make a vertical slit down one side of each pepper, then remove and discard the stem, seeds, and veins. Set prepared peppers aside.

Preheat the oven to 350°F and grease a 2-quart or 9x9-inch baking dish with cooking spray or olive oil.

Layer three roasted peppers in the dish, then sprinkle with 1 cup Monterey Jack cheese and ½ cup Colby Jack cheese. Repeat with the remaining peppers and shredded cheese.

In a medium bowl, whisk together the eggs, milk, flour, baking powder, salt, garlic powder, onion powder, oregano, and black pepper until fully combined.

Pour the egg mixture evenly over the layered cheese and poblanos in the baking dish.

Bake for 45 minutes until the casserole is puffed in the center, and the eggs are set and golden around the edges.

Allow the casserole to cool for 10 minutes before serving. Garnish with chopped cilantro and enjoy.