Whisk the Eggs: In a large bowl, crack all 10 eggs and whisk them together with the whole milk until well combined and smooth, about 1 minute.
Season the Mixture: Add the garlic powder, onion powder, smoked paprika, salt, and black pepper to the egg mixture and whisk until the seasonings are fully incorporated.
Combine with Vegetables and Meat: Fold in the thawed hash browns, 1 cup of the shredded cheddar cheese, crumbled bacon, cooked sausage, diced bell pepper, and diced yellow onion until everything is evenly distributed throughout the egg mixture.
Prepare the Dish: Preheat your oven to 350°F and spray a 9x13-inch baking dish with nonstick cooking spray.
Pour the Mixture: Pour the entire egg and meat mixture into the prepared baking dish, spreading it evenly with a spatula.
Add the Cheese Topping: Sprinkle the remaining 1/2 cup of shredded cheddar cheese evenly over the top of the casserole.
Bake: Place the baking dish in the preheated oven and bake for 30-35 minutes, until the eggs are set and the top is lightly golden, and a knife inserted into the center comes out clean.