Overnight Breakfast Casserole Recipe
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Beat the morning rush with this overnight breakfast casserole! It’s loaded with fluffy eggs, savory sausage, tender mushrooms, and melty cheese – a hearty, incredibly tasty meal that the whole family will love. Prep it the night before, pop it in the oven when you wake up, and voilà – breakfast is served with zero stress.
Mornings can be such a whirlwind, right? Between getting ready for the day, helping the kids out the door, or entertaining overnight holiday guests, the last thing anyone wants to worry about is figuring out what to make for breakfast. We can only have so much toast in a week, and a quick grab-and-go granola bar isn’t exactly the most exciting way to start the day.
Good thing make-ahead breakfasts exist! My family’s favorite – overnight breakfast casserole. I love that I’m able to serve a hearty, all-in-one meal so effortlessly in the early morning or for brunch. It’s got protein, starch, vegetables, and all the flavors you’d want in a warm, comforting dish. It’s a wake-and-bake situation, so we can all enjoy slower, more relaxed mornings.
This make-ahead breakfast casserole makes the perfect Christmas day breakfast, but it’s also great for quick weekday meals and weekend brunches. Leftovers are a great addition to my kids’ lunchboxes and my husband enjoys it as an afternoon snack!
Why You’ll Love This Recipe
- Easiest breakfast: Prep for 20 minutes, sleep, and bake fresh in the morning. The best part? You’ll wake up to a clean kitchen with no dirty dishes.
- Simple ingredients: This recipe calls for easy ingredients you probably already have on hand, making it easy to whip up anytime.
- Feeds a crowd: One batch can feed up to 12, perfect for big families or for entertaining.
- Hearty breakfast: Everything you love about breakfast wrapped up in one dish – bread, cheesy eggs, sausage, and veggies!
- Holiday-worthy: A wonderfully easy breakfast to share with family on busy holiday mornings, including Christmas, Thanksgiving, and Easter!
- Infinitely adaptable: Mix and match your favorite meats, cheeses, and vegetables – you can easily make this recipe your own.
How to Make Overnight Breakfast Casserole
This may be the easiest make-ahead breakfast casserole you’ll ever put together. All you need is a few minutes of prep at night and simply pop it in the oven when you wake up. You can relax or get ready while it bakes to perfection. It’s mornings made effortless with this filling, satisfying one-pan dish!
Scroll to the bottom of this post for a printable recipe card with a full list of ingredients, measurements, and step-by-step instructions.
Ingredients You Need
- Bread: Soaks up moisture to prevent the dish from being soggy. I like crusty bread like sourdough because it gives a great texture. However, you may prefer a soft crustless option. Follow your personal preference and use what you have on hand or what your family likes. Leftover dinner rolls or hamburger buns work, too!
- Pork sausage: For some meaty goodness. I use mild pork sausage, but feel free to use your favorite. I would avoid flavored sausages to avoid overpowering the other flavors in the dish.
- Mushrooms
- Red bell pepper
- Onions
- Eggs: The base that holds everything together.
- Cheddar cheese: For that delicious cheesy punch. Shredded sharp cheddar cheese is best for this recipe. I prefer freshly-grated over the pre-shredded kind because it melts better.
- Milk: Makes the casserole creamy. I use whole milk. You can use any milk, except for low-fat or fat-free since they won’t help achieve the texture we’re going for.
- Salt
- Ground black pepper
Step-By-Step Instructions
Ready to make overnight breakfast casserole? Just follow 4 simple steps – cook the ingredients quickly, assemble, and refrigerate overnight. Leave it to bake in the oven in the morning for a stress-free, delicious breakfast!
Step 1: Prep
Grease a 9×13-inch baking dish and arrange the bread in a single layer across the bottom. This is best with day-old or slightly stale bread. If you only have fresh bread, leave 4 cups out overnight or dry it in the oven for 10 minutes at 300F. Do not brown or toast it, just remove some moisture.
Step 2: Cook
Use a sharp knife to slice open the sausage casing and remove the meat. Alternatively, you can thinly slice the sausage. Brown the meat in a skillet over medium heat. Break it up into small pieces. Then add the mushrooms, bell pepper, and onion and saute for 4 minutes until soft.
Step 2: Assemble
Next, spread the meat and vegetables over the bread and sprinkle green onion evenly over the top. Whisk the eggs, cheese, milk, salt, and pepper in a medium bowl. Pour over the meat.
Cover with plastic wrap or aluminum foil and refrigerate overnight.
Step 4: Bake
When ready to bake, move to room temperature while the oven preheats to 350 F. Uncover and bake the casserole for 50 minutes or until the center is set and a knife inserted to the center comes out clean. The edges should be golden brown. Cool for 15 minutes before serving warm.
Substitutions
Don’t have all the ingredients on hand? Or maybe you want to try something different? Here are some ideal ingredient substitutions for this make ahead breakfast casserole:
- Bread: Don’t want to use bread? Use shredded hash brown instead. 1 (30-ounce) package will do the trick.
- Pork sausage: If you don’t have sausage on hand, use crumbled bacon or diced ham instead.
- Cheddar cheese: If you prefer to use another type of cheese, Monterey jack, Pepper jack, Gouda, Gruyere, or Havarti are all great options.
- Milk: If you want a creamier casserole, substitute the milk with half and half, cream, or evaporated milk.
Variations
One dish, endless options. One of the best things about this overnight breakfast casserole is that it leaves plenty of room for your creativity. You can easily switch things up based on your preferences or what you have on hand. Here are some variations to keep it fun and exciting:
- Skip the sausage and load up on more veggies like spinach, zucchini, and cherry tomatoes for a plant-based option.
- Want a sweet and savory breakfast casserole? Add some diced apples to the mix!
- Stir in a couple of spoonfuls of pesto and top with fresh mozzarella for an Italian flair.
- Pile on bacon, sausage, and diced ham for the ultimate protein-packed breakfast. You can even throw in some cooked ground beef or turkey for an extra meaty option!
- Use spicy sausage or chorizo and add jalapeños for some heat. Top with a drizzle of hot sauce if you like it extra spicy!
- I like to serve this casserole Southwest style from time to time by adding cooked black beans, corn, and jalapeños, then finishing off with a sprinkle of cheddar and cilantro. Perfect for dinner!
Expert Tips
- Cook watery veggies: If using watery vegetables like mushrooms or spinach, sauté them first to prevent excess moisture from making the casserole too wet.
- Cover while baking: If the top starts to brown too quickly, cover the casserole loosely with foil for the last 10 minutes of baking.
- Don’t over-bake: Keep an eye on the casserole toward the end of baking. You want it to be set but still soft and fluffy inside. You’ll know it’s ready when the edges are golden brown and the center is just slightly jiggly, indicating it’s perfectly cooked without being dry.
- Rest after baking: After baking, let the casserole sit for 15 minutes before cutting into it. This helps it firm up and makes slicing easier.
- Serve with fresh toppings: Add some freshness to the dish with chopped herbs, salsa, or avocado slices just before serving to brighten up the rich flavors.
How to Store This Recipe
Transfer leftovers into an airtight container and store in the refrigerator for up to 5 days. You can also freeze the whole pan or individual portions for easy reheating. Just cool completely, place in freezer-safe airtight containers, and freeze for up to 1 month. To reheat, warm individual portions in the microwave or the whole pan in the oven at 350 F until heated through.
To freeze an unbaked casserole, cover the pan with plastic wrap then freeze for up to 1 month. Thaw overnight in the fridge and let it come to room temperature before baking according to recipe instructions.
What to Serve with Overnight Breakfast Casserole
Make-ahead breakfast casserole can be a complete meal on its own. However, feel free to round out your breakfast with some fresh fruit and yogurt.
For brunch, serve the casserole with some pastries like flaky croissants, muffins, or scones, additional breakfast meats like maple bacon or sausage links, or a side of hashbrowns or home fries. Freshly brewed coffee, hot chocolate, breakfast smoothies, or herbal teas all complement this savory dish.
If you make this overnight breakfast casserole, please leave a review. I really appreciate each and every 5-star rating and review comment!
Make Ahead Breakfast Casserole Recipe
Ingredients
- 4 cups crusty bread cubed
- 1 pound pork sausage
- 1 cup sliced mushrooms
- 1 medium red bell pepper diced
- 4 green onions thinly sliced
- 12 large eggs
- 2 cups cheddar cheese shredded
- 1 cup milk
- ½ teaspoon salt
- ½ teaspoon ground black pepper
Instructions
- Grease a 9×13-inch baking dish and arrange the bread in a single layer across the bottom.
- Use a sharp knife to slice open the sausage casing and remove the meat. Alternatively, you can thinly slice the sausage.
- Brown the meat in a skillet over medium heat. Break it up into small pieces. Add the mushrooms, bell pepper and onion and saute for 4 minutes until soft.
- Spread the meat and vegetables over the bread. Sprinkle green onion evenly over the top. Whisk the eggs, cheese, milk, salt, and pepper in a medium bowl. Pour over the meat. Cover with plastic wrap or aluminum foil and refrigerate overnight.
- When ready to bake, move to room temperature while the oven preheats to 350 °F.
- Uncover and bake the casserole for 50 minutes or until the center is set and a knife inserted to the center comes out clean. The edges should be golden brown. Cool for 15 minutes before serving warm.
Notes
- If using watery vegetables like mushrooms or spinach, sauté them first to prevent excess moisture from making the casserole too wet.
- If the top starts to brown too quickly, cover the casserole loosely with foil for the last 10 minutes of baking.
- Keep an eye on the casserole toward the end of baking. You want it to be set but still soft and fluffy inside. You’ll know it’s ready when the edges are golden brown and the center is just slightly jiggly.
- After baking, let the casserole sit for 15 minutes before cutting into it. This helps it firm up and makes slicing easier.
- Add some freshness to the dish with chopped herbs, salsa, or avocado slices just before serving to brighten up the rich flavors.
