In a large mixing bowl, whisk together the eggs, milk, salt, pepper, garlic powder, onion powder, and paprika until well combined.
In a greased 9x13 inch baking dish, layer the torn croissant pieces evenly across the bottom.
Sprinkle the cooked sausage and shredded cheddar cheese over the croissant pieces.
Pour the egg mixture evenly over the croissant, sausage, and cheese layers, ensuring everything is well soaked.
Cover the dish with plastic wrap and refrigerate for at least 4 hours, or overnight for best results.
Preheat the oven to 350°F (175°C).
Remove the casserole from the refrigerator and let it sit at room temperature for about 15 minutes before baking.
Bake uncovered for 35-40 minutes, or until the casserole is puffed and golden brown on top.
Let it cool for a few minutes before slicing. Garnish with fresh parsley if desired.