In a large mixing bowl, whisk together the eggs, milk, salt, black pepper, garlic powder, and onion powder.
Grease a 9x13-inch baking dish with cooking spray or butter.
Layer the cubed bread evenly in the dish.
Sprinkle the cooked sausage and chopped vegetables over the bread.
Pour the egg mixture over the bread, sausage, and vegetables, ensuring an even distribution.
Top the casserole with shredded cheese.
Cover the dish tightly with plastic wrap and refrigerate overnight.
Preheat the oven to 350°F (175°C) the next morning.
Bake uncovered for 50-60 minutes, or until golden brown and set in the center.
Let the casserole cool for a few minutes before slicing and serving.