Preheat oven to 400 degrees F and grease a 9x13 baking dish.
In a large bowl, whisk together eggs and milk until well combined. Add in salt, pepper, minced onion, and garlic powder. Stir.
Add in cereal and sausage. Mix until well combined. Spread evenly in baking dish and top with cheese. Bake for 20 to 25 minutes, or until eggs are fully cooked through. Enjoy!