Step 1

Cook the sausage in a large nonstick skillet over medium-high heat until browned and cooked through, 6 to 8 minutes. Using a slotted spoon, transfer the sausage to a bowl to cool slightly and discard any fat left behind in the skillet.

Step 2

Coat the insert of a 6-quart slow cooker with cooking spray. Layer half of the hash brown potatoes with half the sausage. Toss the bell peppers with the Cheddar, red onion and 1 cup of the mozzarella. Layer half the mixture over the sausage, then repeat the layering with the remaining potatoes, sausage and vegetable-cheese mixture.

Step 3

Whisk the eggs, milk, paprika, 1/2 teaspoon salt and 1/4 teaspoon black pepper in a large bowl, then pour over the casserole mixture. Sprinkle the top with the remaining 1 cup mozzarella, then cover and cook on low until the eggs are set and have become a custard, about 7 hours. Turn off the heat, uncover and let rest for about 10 minutes.

Step 4

Sprinkle with sliced scallions and serve with hot sauce and ketchup.