Preheat the oven to 350°F (175°C).
Prepare the baking dish by greasing a 9x9-inch pan with non-stick spray or butter.
Crack the eggs into a large bowl. Add the milk, garlic powder (if using), salt, and pepper. Whisk until everything is well combined.
Stir in the cheese and chopped bacon or sausage pieces.
Pour the mixture into the prepared baking dish, spreading it out evenly.
Bake in the preheated oven for 25 to 30 minutes, or until the edges are golden and the center is set.
Remove from the oven and let it cool for a few minutes.
Cut into squares and serve warm.