The Best Christmas Breakfast Casserole (Easy & Make-Ahead!)

I can still smell it. The rich, savory aroma of sausage, eggs, and cheese baking in the oven, mingling with the scent of the fresh pine from ur Christmas tree. For me, that is the official scent of Christmas morning.

The sound of my three little ones thundering down the stairs, their eyes wide with excitement, is the soundtrack. In the midst of the happy chaos of unwrapping presents and squeals of delight, the last thing I want to do is stand over a hot stove. That’s where this incredible Christmas breakfast casserole comes in. It’s more than just a recipe; it’s a tradition.

Years ago, I realized I was missing the magic of the morning because I was too busy flipping pancakes and frying bacon. I wanted to be on the floor with my kids, sipping my coffee, and soaking it all in. I needed a solution—a delicious, hearty, and most importantly, a make-ahead holiday breakfast.

This casserole was my answer. You do all the simple prep work on Christmas Eve, and then on Christmas morning, you just pop it in the oven. The result is a warm, comforting, and utterly delicious meal that feeds the whole family.

It allows you to be present for the moments that matter. This recipe has become our cherished tradition, and I’m so excited to share it with you so you can make it one of yours, too.

Why You’ll Love This Holiday Breakfast Casserole

This recipe is a true game-changer for any busy holiday morning. Besides being incredibly delicious, here are a few key reasons why this will become your go-to Christmas breakfast:

• Perfectly Make-Ahead: This is the ultimate stress-reducer. You assemble the entire casserole the night before, cover it, and let it chill in the fridge. The overnight rest actually makes it taste even better as the flavors meld together beautifully.
• Simple, Everyday Ingredients: You won’t need to make a special trip to the store for fancy ingredients. This recipe uses pantry and refrigerator staples like bread, sausage, eggs, and cheese. It’s nourishing, simple, and budget-friendly.
• A True Crowd-Pleaser: From picky toddlers to hungry teenagers and visiting grandparents, everyone loves this dish. It’s hearty, cheesy, and packed with savory flavor that feels both special and comforting.
• Endlessly Customizable: Think of this recipe as a fantastic starting point. You can easily swap proteins, add vegetables, or try different cheeses to make it perfectly your own. I’ll share some of my favorite variations below!

Ingredients You’ll Need

The beauty of this casserole lies in its simplicity. These basic ingredients combine to create something truly special. Here’s what you need to gather.

Ingredient	Quantity	Notes
Ground Pork Sausage	1 lb	A mild or medium breakfast sausage works best. You can also use maple or spicy sausage.
Day-Old Bread	8-10 cups, cubed	Slightly stale bread is key! A sturdy white bread, brioche, or sourdough works wonderfully.
Large Eggs	10	These create the rich, savory custard that holds everything together.
Whole Milk	3 cups	For the richest custard, use whole milk. You can substitute 2% if needed.
Sharp Cheddar Cheese	2 cups, shredded	Shredding your own cheese from a block provides the best melt.
Dry Mustard Powder	1 tsp	This little secret ingredient enhances the cheese and egg flavor without tasting like mustard.
Salt	1 tsp	Adjust to your taste, as sausage and cheese can be salty.
Black Pepper	1/2 tsp	Freshly ground pepper is always best for maximum flavor.
Green Onions or Chives	1/4 cup, chopped	Optional, for garnish and a touch of fresh flavor.

Substitutions & Variations

One of the best things about a casserole is how forgiving it is. Feel free to get creative and use what you have on hand. Here are some of our family’s favorite ways to switch things up.

• Protein Power: Instead of sausage, try using 1 pound of cooked and crumbled bacon, diced ham (a great way to use holiday leftovers!), or even chorizo for a spicy kick. For a vegetarian option, use a plant-based sausage crumble or an equal amount of sautéed mushrooms and spinach.
• Bread Choices: Don’t have stale white bread? No problem! Cubed croissants create an incredibly rich and flaky version. Sourdough adds a wonderful tangy flavor, and challah or brioche will give you a sweeter, more decadent custard. You can also use a quality gluten-free bread to accommodate dietary needs.
• Cheese, Please: While sharp cheddar is a classic, feel free to experiment. A mix of Gruyère and Swiss adds a nutty, complex flavor. Monterey Jack or a Colby blend are great for a milder taste and excellent meltability. For a little heat, add some Pepper Jack!
• Veggie Boost: This is a great way to add extra nutrients. Sauté 1 cup of diced bell peppers and onions with your sausage. Wilted spinach, sautéed mushrooms, or even some diced jalapeños for the adventurous are all fantastic additions. Just be sure to cook the vegetables first to release their moisture.

Step-by-Step Instructions

Follow these simple steps to assemble your casserole the night before for a completely stress-free Christmas morning.

1. Prepare Your Pan: First, generously grease a 9×13 inch baking dish with butter or non-stick cooking spray. This crucial step ensures nothing sticks and makes cleanup much easier later.
2. Cook the Sausage: Next, place a large skillet over medium-high heat. Add the ground sausage and cook it, breaking it apart with a spatula, until it is fully browned and no pink remains. This usually takes about 8-10 minutes. Afterward, drain any excess grease from the skillet.
3. Layer the Casserole: Now, you will build your layers. Spread half of the bread cubes evenly across the bottom of your prepared baking dish. Sprinkle the cooked sausage over the bread, followed by 1 ½ cups of the shredded cheddar cheese. Finally, top with the remaining bread cubes.
4. Create the Egg Custard: In a large bowl, whisk the 10 eggs until they are well-beaten and light yellow. Then, whisk in the milk, dry mustard, salt, and pepper until everything is thoroughly combined and smooth.
5. Pour and Combine: Carefully and evenly pour the egg mixture over the layers of bread, sausage, and cheese in the baking dish. Gently press down on the top layer of bread with a spatula to help it absorb the custard.
6. Top and Chill (The Magic Step!): Sprinkle the remaining ½ cup of cheese over the top. Cover the dish tightly with plastic wrap or foil and place it in the refrigerator to chill for at least 8 hours, or preferably overnight. This resting period is essential for the bread to soak up all that delicious custard.
7. Bake to Golden Perfection: On Christmas morning, preheat your oven to 350°F (175°C). Remove the casserole from the refrigerator and let it sit on the counter for about 20-30 minutes to take the chill off. Uncover the dish and bake for 45-55 minutes, or until the center is set (it shouldn’t jiggle) and the top is golden brown and bubbly. If it starts to brown too quickly, you can loosely tent it with foil for the last 10-15 minutes of baking.
8. Rest and Serve: Let the casserole rest for 10 minutes before slicing. This helps it set up properly. Garnish with fresh chives or green onions and serve warm. Enjoy the smiles!

Pro Tips for Success

Over the years, I’ve learned a few little tricks that take this Christmas breakfast casserole from great to absolutely perfect.

• Stale Bread is Your Best Friend: I can’t stress this enough! Fresh, soft bread will turn mushy. If your bread is fresh, you can cube it and toast it in the oven at 300°F for about 10-15 minutes, or simply leave the cubes out on the counter for a few hours to dry out.
• Don’t Skip the Overnight Chill: I know it’s tempting to bake it right away, but the magic happens in the fridge. This time allows the bread to become fully saturated with the egg custard, resulting in a perfectly textured, cohesive casserole rather than a soggy mess.
• Shred Your Own Cheese: Pre-shredded cheeses are coated with starches to prevent clumping, which can affect how they melt. For the creamiest, gooiest cheese pull, take a few extra minutes to shred a block of cheese yourself. You’ll taste the difference.
• Bring to Room Temperature: Letting the casserole sit on the counter for 20-30 minutes before baking helps it cook more evenly. Placing an ice-cold glass dish into a hot oven can sometimes cause it to crack, so this is a good safety measure as well.

Storage & Reheating Tips

One of the best parts about this casserole is that the leftovers are just as delicious! Here’s how to store and enjoy it later.

• To Store: Allow the casserole to cool completely. Then, cover the baking dish tightly with foil or plastic wrap, or transfer individual portions to an airtight container. You can store it in the refrigerator for up to 4 days.
• To Reheat: For the best results, reheat individual slices in the oven or a toaster oven at 350°F for 10-15 minutes until warmed through. This will help crisp up the top again. If you’re in a hurry, you can also reheat a slice in the microwave for 60-90 seconds, but the texture will be softer.
• To Freeze: You can freeze the baked and cooled casserole for up to 3 months. Wrap the entire dish (or individual slices) tightly in plastic wrap, followed by a layer of aluminum foil. Thaw it overnight in the refrigerator before reheating as directed above.

What to Serve With This Recipe

This savory Christmas breakfast casserole is a hearty meal all on its own, but it also plays beautifully with a few simple sides to round out your holiday brunch. We love to serve it with:

• A fresh and vibrant Fruit Salad with seasonal fruits like oranges, pomegranates, and kiwi.
• Simple Sliced Avocados or Tomatoes for a fresh, creamy contrast.
• For a sweeter element, some warm Cinnamon Rolls or Monkey Bread are always a hit.
• And of course, plenty of freshly brewed Coffee, Tea, and Orange Juice for everyone.

FAQs About This Christmas Breakfast Casserole

Can I assemble this Christmas breakfast casserole the morning I plan to bake it?

You certainly can, but I highly recommend the overnight chill. If you’re short on time, let it rest for at least 2 hours in the refrigerator to give the bread a chance to absorb some of the egg mixture. The texture and flavor will be much better with a longer rest.

How do I know when the casserole is fully cooked?

The casserole is done when the top is golden brown and the center is set. To check for doneness, gently shake the pan. If the center has a significant jiggle, it needs more time.

A very slight, minimal wobble is okay, as it will continue to set as it rests. You can also insert a knife into the center; if it comes out clean, it’s ready.

Can I make this recipe gluten-free?

Absolutely! Simply substitute your favorite gluten-free bread. Make sure it’s a sturdy variety that will hold up to the custard. As with regular bread, it’s best if it’s a day or two old or slightly toasted to help it absorb the liquid without falling apart.

Can I use something other than whole milk?

Yes, you can. While whole milk provides the richest and creamiest custard, you can substitute it with 2% milk or even a mixture of half-and-half and milk. I would avoid skim milk, as it can result in a watery texture. For a dairy-free option, unsweetened almond or soy milk can work, though the custard may be slightly less rich.

Final Thoughts

Food is so much more than just fuel; it’s a way we show our love. This Christmas breakfast casserole is a hug in a dish. It’s the simple, reliable, and delicious recipe that lets me be a part of the joy instead of being stuck in the kitchen.

It’s the taste of home, of family, and of a Christmas morning spent together. I hope this recipe brings as much warmth and happiness to your holiday table as it has to mine. From my kitchen to yours, Merry Christmas!

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