Preheat your oven to 375°F (190°C).

In a large mixing bowl, whisk together the eggs and milk until well combined.

Add the cubed bread, shredded cheese, diced ham or cooked breakfast sausage, and salt and pepper to the bowl, and stir until all ingredients are evenly distributed.

Grease a 9x9 inch baking dish with cooking spray, and pour the egg mixture into the dish.

Bake for 30-35 minutes, or until the casserole is golden brown and set in the center.

Let cool for a few minutes before slicing and serving.