Overnight Breakfast Casserole Recipe

Who doesn’t love waking up to a hot, comforting breakfast with minimal morning effort? This overnight breakfast casserole is my go-to when I want something hearty and delicious ready to go in the morning. It’s packed with savory flavors from seasoned breakfast sausage, crispy beef bacon, and creamy cheese, all nestled in a bed of fluffy potatoes. The best part? You prep everything the night before, so all you have to do is pop it in the oven while the coffee brews.

I first discovered this recipe during a holiday weekend when I was entertaining guests and didn’t want to spend my entire morning in the kitchen. I wanted something warm and filling to serve a crowd without standing over the stove flipping pancakes or making individual omelets. Enter: this easy-to-prep casserole. It was a lifesaver then, and now, it’s become a regular part of our weekend breakfast rotation. Let’s dive into how you can make it too!

this RECIPE

A morning favorite: the story behind this dish 🌞

The beauty of a breakfast casserole is how versatile and adaptable it is. Recipes like this have been around for decades, often made for large family gatherings, potlucks, or holiday breakfasts. Originally, casseroles were a simple way to throw together what was on hand—meat, eggs, cheese, and some form of bread or potatoes—and bake it all in one dish. Over time, people have perfected the formula, adding their personal touches to make it their own. What I love most is how flexible it is; once you understand the basics, you can switch things up with the ingredients and flavors depending on your cravings or what you have in your fridge.

Let’s talk ingredients: bringing it all together

The key to a delicious breakfast casserole lies in the ingredients you choose. Here’s a breakdown of what makes this one stand out:

• Breakfast beef sausage: This adds a rich, savory flavor that forms the foundation of the dish. If you’re looking for a lighter option, turkey sausage works just as well.
• Beef bacon: The crispy bits of bacon mixed throughout add a crunchy, salty bite that contrasts beautifully with the soft eggs and potatoes. You can also substitute turkey bacon for a leaner option, though the beef bacon gives it a robust flavor.
• Eggs: This is the heart of the casserole. You want to whisk the eggs until they’re light and fluffy so they bake into a soft, pillowy texture. Don’t skimp here—this is what binds everything together!
• Shredded potatoes: Hash browns give the casserole a great texture and absorb all the rich flavors from the sausage and eggs. If you prefer, you can use sweet potatoes for a slightly sweeter, more nutritious twist.
• Cheddar cheese: Half of the cheese gets mixed into the casserole for a gooey, melty base, while the other half is sprinkled on top to create a golden, bubbly crust. You can experiment with other cheeses like Monterey Jack or pepper jack for extra flavor.
• Green onions (optional): These add a pop of color and a subtle onion flavor, brightening up the entire dish.

Kitchen gear you’ll need (and what you can skip)

This recipe doesn’t require any fancy gadgets—just a few basics you likely already have in your kitchen:

• A large skillet: For browning the sausage and cooking the beef bacon. A cast iron skillet works well, but any non-stick pan will do.
• Mixing bowls: One for whisking the eggs and another for mixing the potatoes, cheese, and meats together.
• A 9×13 baking dish: This size is perfect for feeding a crowd and gives you enough space to layer everything evenly. If you don’t have this exact size, any similarly-sized casserole dish will work.
• Whisk: To get those eggs light and fluffy. If you don’t have a whisk, a fork will work in a pinch, but a whisk will give you a more even mixture.

Step-by-step: how to make your casserole foolproof

Now, let’s walk through making this casserole together:

1. Pre-cook the meats: Start by browning your breakfast sausage in a skillet over medium heat. Break it up as it cooks to ensure it’s in small crumbles. Once cooked through, remove the sausage, drain any excess grease, and cook the beef bacon in the same pan until crispy.
2. Whisk the eggs: In a large bowl, whisk together the eggs, milk, mustard, salt, and pepper. This mixture forms the base of the casserole and will bake into a fluffy, savory custard.
3. Mix it all together: In another large bowl, combine the shredded potatoes, half of the cheese, the cooked sausage, and half of the crispy beef bacon. Pour the egg mixture over the top and stir everything together until well combined.
4. Assemble the casserole: Grease your baking dish, then pour the mixture in, spreading it out evenly. Cover the dish tightly with foil or plastic wrap and refrigerate overnight.
5. Bake in the morning: When you’re ready to bake, preheat your oven to 350°F. Remove the wrapping, sprinkle the remaining cheese over the top, and bake for 45-60 minutes, until the center is set and not jiggly. (A helpful tip: If you’re unsure, poke a knife into the center—if it comes out clean, the casserole is done!)
6. Top and serve: Once out of the oven, let the casserole cool slightly. Top with the remaining crispy beef bacon and a sprinkling of green onions for added color and flavor.

Variations I’ve tried and loved

This casserole is perfect as-is, but I’ve had fun experimenting with a few different versions:

• Vegetarian option: Skip the sausage and beef bacon, and add in sautéed mushrooms, bell peppers, and spinach for a hearty veggie-packed version. You won’t even miss the meat!
• Gluten-free: Thankfully, this recipe is naturally gluten-free if you use gluten-free sausage. Just double-check your hash browns and cheese to make sure they’re gluten-free too.
• Spicy twist: For a bit of heat, swap out the cheddar for pepper jack and add some diced jalapeños or a sprinkle of crushed red pepper flakes into the egg mixture. You can also use spicy sausage if you like things extra hot.
• Seasonal variation: In the fall, try using sweet potatoes in place of the shredded potatoes and a sharp white cheddar. You could even sprinkle a little cinnamon into the egg mixture for a subtle, warm flavor.

Serving and presentation ideas

If you’re serving this for a brunch gathering, I love to place the casserole in the center of the table in its baking dish. Sprinkle some extra green onions on top and maybe a little fresh parsley for a pop of color. This dish pairs well with fresh fruit, like a bowl of mixed berries or a fruit salad on the side.

For a cozy family breakfast, I like to serve it in individual squares, with a dollop of sour cream or a drizzle of hot sauce for extra flavor. You can even toast up some thick slices of bread to go with it!

Recommended beverages to pair with your meal

This casserole is rich and hearty, so a refreshing beverage is a must. Here are a few non-alcoholic drinks I love to pair it with:

• Freshly squeezed orange juice: The bright citrus cuts through the richness of the casserole, adding a burst of freshness to your meal.
• Herbal tea: Something like chamomile or peppermint tea complements the savory flavors without overpowering them.
• Iced coffee: If you’re like me and love a morning caffeine boost, a lightly sweetened iced coffee or cold brew balances out the casserole beautifully.
• Fruit-infused water: Add slices of cucumber, lemon, and mint to a pitcher of water for a refreshing, hydrating drink that’s perfect for brunch.

Storing and reheating tips

If you’ve got leftovers (which is rare in my house!), store them in an airtight container in the fridge. They’ll keep well for about 3-4 days. To reheat, just pop a slice in the microwave for 1-2 minutes until warmed through, or reheat in the oven at 350°F for about 15 minutes to keep the top nice and crispy. If you’re freezing leftovers, wrap individual slices in foil and freeze for up to 2 months—just thaw in the fridge overnight and reheat as usual.

Adjusting for different serving sizes

This recipe easily feeds 6-8 people, but if you’re cooking for a smaller group, you can halve the ingredients and bake the casserole in an 8×8 dish instead. On the flip side, if you’re hosting a bigger crowd, you can double the recipe and bake it in two 9×13 dishes. One thing to note: the cooking time might vary slightly if you change the size, so keep an eye on the casserole while it bakes.

FAQs

1. Can I use a different kind of cheese?
Yes! Any melting cheese will work well in this casserole. Monterey Jack, pepper jack, or even mozzarella would be delicious.

2. How do I know when the casserole is done?
The center should be set and not jiggly when the casserole is done. You can also stick a knife into the middle—if it comes out clean, you’re good to go!

3. Can I prep this ahead of time?

Absolutely! That’s the beauty of this recipe. You can prep it the night before and just bake it in the morning.

4. Can I freeze the casserole?
Yes, you can freeze it before baking or after. If freezing before, make sure it’s tightly wrapped. If freezing leftovers, wrap individual portions for easy reheating.

5. Can I add vegetables to this casserole?
Definitely! Bell peppers, mushrooms, and spinach all work great in this dish. Just sauté them first to avoid excess moisture.

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