Cheesy Breakfast Casserole

Meta Description: This cheesy breakfast casserole is loaded with fluffy eggs, savory sausage, melted cheese, and golden potatoes. An easy make-ahead breakfast perfect for holidays and family gatherings.

This Cheesy Breakfast Casserole is the ultimate comfort-food breakfast! It’s hearty, creamy, cheesy, and incredibly easy to prepare. Made with fluffy eggs, savory sausage, tender potatoes, and plenty of melted cheese, this casserole is perfect for busy mornings, weekend brunches, holidays, and family gatherings.

The best part is that you can assemble it the night before and simply bake it in the morning.

Ingredients

1 pound breakfast sausage
8 large eggs
1 cup whole milk
1 cup sour cream
2 cups shredded cheddar cheese
1 cup shredded mozzarella cheese
3 cups frozen diced hash browns
½ cup diced onion
½ cup diced bell pepper
½ teaspoon garlic powder
½ teaspoon onion powder
½ teaspoon salt
¼ teaspoon black pepper
2 tablespoons chopped fresh parsley, optional
2 tablespoons butter or cooking oil

Instructions

1. Prepare the Oven

Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish with butter or nonstick cooking spray.

2. Cook the Sausage

Heat a large skillet over medium heat. Add the breakfast sausage and cook for 6–8 minutes, breaking it apart with a wooden spoon as it cooks.

Once browned and fully cooked, drain any excess grease. Set the sausage aside.

3. Sauté the Vegetables

Add the butter or oil to the same skillet. Add the diced onion and bell pepper.

Cook for about 3–4 minutes, until the vegetables soften slightly. Remove from the heat.

4. Prepare the Egg Mixture

Crack the eggs into a large bowl. Add the milk and sour cream and whisk until smooth.

Stir in the garlic powder, onion powder, salt, and black pepper.

For an especially creamy casserole, make sure the sour cream is fully incorporated into the eggs.

5. Assemble the Casserole

Spread the frozen hash browns evenly across the bottom of the prepared baking dish.

Add the cooked sausage, followed by the sautéed onion and bell pepper.

Sprinkle 1½ cups of cheddar cheese and ½ cup of mozzarella cheese over the top.

Pour the egg mixture evenly over everything, making sure it reaches all the corners of the dish.

Finish with the remaining cheddar and mozzarella cheese.

6. Bake

Place the casserole in the preheated oven and bake uncovered for approximately 40–50 minutes.

The casserole is ready when the eggs are completely set in the center and the cheese is melted, bubbling, and lightly golden.

If the cheese begins browning too quickly, loosely cover the dish with aluminum foil for the remaining baking time.

7. Rest and Serve

Remove the casserole from the oven and let it rest for 5–10 minutes before slicing.

Garnish with fresh parsley and cut into squares.

Serve warm with fresh fruit, toast, biscuits, or a simple green salad.

Make-Ahead Instructions

This casserole is perfect for preparing ahead of time. Assemble everything in the baking dish, cover tightly, and refrigerate overnight.

The next morning, remove it from the refrigerator while the oven preheats. Bake as directed, adding approximately 5–10 extra minutes if needed.

Easy Variations

You can customize this cheesy breakfast casserole with your favorite ingredients:

Bacon: Replace the sausage with cooked crispy bacon.
Ham: Add diced cooked ham for a delicious breakfast-ham version.
Vegetables: Add spinach, mushrooms, tomatoes, or broccoli.
Extra cheesy: Add Monterey Jack, pepper Jack, or Colby cheese.
Spicy: Add diced jalapeños or a pinch of red pepper flakes.
Meat-free: Leave out the sausage and add extra vegetables.

Storage

Store leftover casserole in an airtight container in the refrigerator for up to 3–4 days. Reheat individual portions in the microwave or oven until heated through.

This Cheesy Breakfast Casserole is warm, filling, and packed with delicious flavors. With crispy potatoes, savory sausage, fluffy eggs, and a generous layer of gooey melted cheese, it’s the kind of breakfast everyone will ask you to make again.