Here is my favorite breakfast casserole recipe, with crispy hash browns, savory breakfast sausage, fluffy eggs, and melted cheese all baked together in one dish.
This breakfast casserole is what I make when I have overnight guests or want to feed my family something hearty on a lazy weekend morning. I love that I can prep it the night before and just pop it in the oven when we wake up. Plus, there’s only one pan to clean up afterwards, which is always a win in my book.
Why You’ll Love This Breakfast Casserole
- Perfect for meal prep – Make this casserole ahead of time and reheat portions throughout the week for quick, satisfying breakfasts when you’re rushing out the door.
- Packed with protein – With eggs and sausage, this dish keeps you full and energized all morning long.
- One-pan wonder – Everything bakes together in a single dish, which means less cleanup and more time enjoying your breakfast.
- Sneaks in veggies – The peppers, onions, and spinach add nutrition and flavor without feeling like you’re eating a salad for breakfast.
- Feeds a crowd – This casserole is great for weekend brunch with family or hosting overnight guests, and everyone can dig in at the same time.
What Kind of Sausage Should I Use?
For this breakfast casserole, you’ll want to grab regular pork breakfast sausage, which you can find in the refrigerated section near the bacon and other breakfast meats. You can go with mild, medium, or hot depending on how much spice you like in the morning – I usually stick with mild so everyone at the table is happy. If you prefer, turkey or chicken breakfast sausage works just as well and gives you a leaner option without sacrificing flavor. Just make sure you’re getting loose sausage rather than links, since you’ll be browning and crumbling it in the pan before adding it to the casserole.
Options for Substitutions
This breakfast casserole is super forgiving when it comes to swaps, so feel free to work with what you have:
- Pork breakfast sausage: Turkey sausage, chicken sausage, or even crumbled bacon work great here. For a vegetarian option, try plant-based sausage or sautéed mushrooms for that savory flavor.
- Red pepper and onion: Use whatever veggies you have on hand – green peppers, mushrooms, zucchini, or tomatoes all work well. Just make sure to dice them small and sauté any watery vegetables first to avoid a soggy casserole.
- Frozen hashbrowns: Fresh grated potatoes work too, but squeeze out excess moisture with a clean kitchen towel before adding them to prevent sogginess. You can also use tater tots for a fun twist.
- Spinach: Kale, Swiss chard, or arugula make good substitutes. If using frozen spinach, thaw it completely and squeeze out all the water before adding.
- Whole milk: Any milk works here – 2%, skim, almond milk, or oat milk. The casserole will be slightly less rich with lower-fat options, but it’ll still taste great.
- Sharp cheddar: Monterey Jack, pepper jack, Swiss, or Gruyere all melt nicely. You can also mix different cheeses for more complex flavor.
Watch Out for These Mistakes While Baking
The biggest mistake with breakfast casseroles is not cooking the sausage completely before adding it to the dish, which can leave you with greasy pools of fat and undercooked meat – make sure to brown it thoroughly and drain off excess grease.
Skipping the step of thawing and squeezing out moisture from frozen hashbrowns will result in a watery casserole, so pat them dry with paper towels or let them sit at room temperature for 20 minutes before assembling.
Another common error is overbaking, which turns the eggs rubbery and dry – your casserole is done when the center is just set and still slightly jiggly, usually around 35-40 minutes, since it will continue cooking as it rests.
For extra flavor, sauté your peppers and onions with the sausage until they’re softened, and if you’re prepping this the night before, wait to add the cheese on top until right before baking so it melts perfectly.
What to Serve With Breakfast Casserole?
This breakfast casserole is pretty filling on its own, but I love serving it with some fresh fruit on the side – think sliced melon, berries, or a simple fruit salad to balance out all the savory flavors. A stack of buttered toast or some warm biscuits are perfect for soaking up any extra egg mixture, and they make the meal feel even more complete. If you’re feeding a crowd for brunch, consider adding some crispy bacon strips or breakfast potatoes on the side, even though the casserole already has hash browns built in. A light arugula salad with a lemon vinaigrette also works nicely if you want something fresh and peppery to cut through the richness of the eggs and cheese.
Storage Instructions
Store: This breakfast casserole is perfect for meal prep! Once it’s cooled down, cover it tightly with foil or plastic wrap and keep it in the fridge for up to 4 days. I love cutting it into squares and grabbing a piece for a quick breakfast throughout the week.
Freeze: You can freeze this casserole whole or in individual portions, which is super handy for busy mornings. Wrap it well in plastic wrap and then foil, or store portions in freezer-safe containers for up to 3 months. I like to freeze individual servings so I can just grab one when I need it.
Reheat: To warm it up, pop a slice in the microwave for about 1-2 minutes, or reheat it in the oven at 350°F for 10-15 minutes until heated through. If you’re reheating from frozen, let it thaw in the fridge overnight first, or add a few extra minutes to the heating time.
| Preparation Time | 15-20 minutes |
| Cooking Time | 25-30 minutes |
| Total Time | 40-50 minutes |
| Level of Difficulty | Medium |
Estimated Nutrition
Estimated nutrition for the whole recipe (without optional ingredients):
- Calories: 2000-2200
- Protein: 110-120 g
- Fat: 150-165 g
- Carbohydrates: 60-75 g
Ingredients
- 1 lb ground pork breakfast sausage
- 3/4 cup diced red bell pepper
- 3/4 cup chopped onion
- 2 cups frozen hash brown potatoes (10 oz)
- 1–2 cups chopped fresh spinach
- 10 large eggs
- 1 tsp kosher salt
- 1/2 tsp ground black pepper
- 1/2 cup whole milk or plain coconut milk
- 1 cup finely shredded sharp cheddar or nondairy cheese, plus extra for topping
Step 1: Prepare the Baking Dish and Preheat Oven
Preheat your oven to 350°F (175°C) to ensure it’s hot and ready for baking.
Meanwhile, lightly grease a 9×13 inch baking dish with butter or nonstick spray to prevent the casserole from sticking.
Step 2: Cook the Sausage, Onion, and Red Pepper
- 1 lb ground pork breakfast sausage
- 3/4 cup diced red bell pepper
- 3/4 cup chopped onion
Heat a skillet over medium-high heat.
Add the ground pork breakfast sausage, diced red bell pepper, and chopped onion.
Break up the sausage with a spatula as it cooks.
Continue cooking until the sausage is no longer pink and the vegetables have softened.
Drain off any excess grease from the skillet to keep the casserole from being greasy.
Step 3: Add Spinach and Cool the Mixture
- 1–2 cups chopped fresh spinach
Add the chopped fresh spinach to the skillet with the cooked sausage mixture.
Cook for an additional 1-2 minutes until the spinach is wilted.
Remove the skillet from the heat and let the mixture cool slightly—this helps prevent the eggs from scrambling when mixed in later.
Step 4: Mix Eggs, Dairy, Hash Browns, and Seasonings
- 10 large eggs
- 1 tsp kosher salt
- 1/2 tsp ground black pepper
- 1/2 cup whole milk or plain coconut milk
- 2 cups frozen hash brown potatoes (10 oz)
- 1 cup finely shredded sharp cheddar or nondairy cheese
In a large mixing bowl, whisk together the eggs, kosher salt, ground black pepper, and whole milk or plain coconut milk until well combined.
Stir in the frozen hash brown potatoes and 1 cup of finely shredded sharp cheddar or nondairy cheese.
This will make the mixture rich and creamy before you add the cooked sausage and vegetable mixture.
Step 5: Combine and Assemble the Casserole
- cooked sausage, onion, red pepper, and spinach mixture from Steps 2 and 3
- egg, milk, cheese, hash brown, and seasoning mixture from Step 4
- extra finely shredded sharp cheddar or nondairy cheese for topping
Add the cooled sausage, onion, red pepper, and spinach mixture from Step 3 into the bowl with the egg mixture.
Stir well until fully incorporated.
Pour the combined mixture into your prepared baking dish and spread evenly.
Sprinkle extra cheese over the top for a delicious melty crust—I always like to add a little extra cheese at this stage for a golden, bubbly topping.
Step 6: Bake the Casserole
Place the assembled casserole in the preheated oven and bake, uncovered, for 25-30 minutes until the eggs are set and the top is golden.
Let the casserole cool slightly before slicing and serving—this helps the pieces hold together neatly.
For extra flavor, I sometimes serve it with a dash of hot sauce on the side.
Hearty Sausage, Egg and Hash Brown Breakfast Casserole
Ingredients
- 1 lb ground pork breakfast sausage
- 3/4 cup diced red bell pepper
- 3/4 cup chopped onion
- 2 cups frozen hash brown potatoes (10 oz)
- 1–2 cups chopped fresh spinach
- 10 large eggs
- 1 tsp kosher salt
- 1/2 tsp ground black pepper
- 1/2 cup whole milk or plain coconut milk
- 1 cup finely shredded sharp cheddar or nondairy cheese, plus extra for topping
Instructions
- Preheat your oven to 350°F (175°C) to ensure it's hot and ready for baking. Meanwhile, lightly grease a 9x13 inch baking dish with butter or nonstick spray to prevent the casserole from sticking.
- Heat a skillet over medium-high heat. Add the ground pork breakfast sausage, diced red bell pepper, and chopped onion. Break up the sausage with a spatula as it cooks. Continue cooking until the sausage is no longer pink and the vegetables have softened. Drain off any excess grease from the skillet to keep the casserole from being greasy.
- Add the chopped fresh spinach to the skillet with the cooked sausage mixture. Cook for an additional 1-2 minutes until the spinach is wilted. Remove the skillet from the heat and let the mixture cool slightly—this helps prevent the eggs from scrambling when mixed in later.
- In a large mixing bowl, whisk together the eggs, kosher salt, ground black pepper, and whole milk or plain coconut milk until well combined. Stir in the frozen hash brown potatoes and 1 cup of finely shredded sharp cheddar or nondairy cheese. This will make the mixture rich and creamy before you add the cooked sausage and vegetable mixture.
- Add the cooled sausage, onion, red pepper, and spinach mixture from Step 3 into the bowl with the egg mixture. Stir well until fully incorporated. Pour the combined mixture into your prepared baking dish and spread evenly. Sprinkle extra cheese over the top for a delicious melty crust—I always like to add a little extra cheese at this stage for a golden, bubbly topping.
- Place the assembled casserole in the preheated oven and bake, uncovered, for 25-30 minutes until the eggs are set and the top is golden. Let the casserole cool slightly before slicing and serving—this helps the pieces hold together neatly. For extra flavor, I sometimes serve it with a dash of hot sauce on the side.
