Preheat the oven to 350°F (175°C).
In a large bowl, whisk together the eggs, whole milk, salt, black pepper, garlic powder, and onion powder until fully combined.
Add the cubed bread to the egg mixture and stir gently to coat all the bread pieces.
Grease a 9×13 inch baking dish with cooking spray or butter.
Layer half of the bread mixture in the bottom of the prepared baking dish.
Sprinkle half of the cooked breakfast sausage evenly over the bread layer.
Sprinkle 1 cup of shredded cheddar cheese over the sausage layer.
Add the remaining bread mixture on top, spreading evenly.
Top with the remaining cooked sausage and shredded cheddar cheese.
Cover the baking dish tightly with aluminum foil.
To freeze: Place the covered casserole in the freezer for up to 3 months.
To bake from frozen: Remove the casserole from the freezer and preheat the oven to 350°F (175°C).
Bake covered for 45 minutes, then remove the foil and bake an additional 15 minutes or until the casserole is set and the cheese is golden and bubbly.
Let the casserole cool for 5 minutes before serving.