Coat a 6 quarter slow cooker with cooking spray.

Arrange the hash browns in an even layer on the bottom of the slow cooker.

Sprinkle half the cheddar cheese over the potatoes and reserve the remaining cheese for later.

Heat a large skillet over medium heat. Add the sausage to the pan and break up into bite sized pieces with a fork or spatula as it cooks. Cook the sausage until no longer pink. Transfer to a bowl with a slotted spoon and drain off all but 1 tablespoon of fat.

Add the ham to the pan and cook for 2-3 minutes. Transfer to the bowl with the sausage.

Add the onion to the pan and cook until beginning to soften. Stir in the bell peppers, mushrooms, garlic and spinach. Continue to cook until beginning to soften.

Add the Italian seasoning and cook for 1 minute.

Add the sausage and ham back to the pan and remove from the heat.

Spread the sausage mixture evenly over the potatoes and cheese.

Whisk together the eggs, garlic powder, onion powder, salt, pepper and half and half.

Pour the egg mixture over the casserole in an even layer and sprinkle with the remaining cheese, do not stir.

Cook on low for 6-7 hours or high for 3-4 hours.

Once cooked, uncover and allow to rest at room temperature for 15 minutes.

Sprinkle with parmesan cheese, green onion and parsley, if using.

Serve hot or room temperature.