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Christmas morning always stirs up a special sort of joy in my kitchen—and nothing brings everyone to the table faster than the smell of a cheesy, savory casserole baking away. I swear, even my sleepy teenagers wander down the stairs hoping for a slice before coffee kicks in! For years, it’s been our family’s tradition to kick off the holiday with this rich, cozy Christmas Breakfast Casserole. It’s loaded with tender breakfast sausage, gooey Cheddar, and toasty bread all bound together by a creamy egg mixture. The best part? You do all the heavy lifting the night before, so when Santa’s work is finally done, all you have to do is pop it in the oven, pour yourself a mug of cocoa, and soak up the holiday magic.
One of my favorite moments is sneaking into the kitchen just before sunrise, hearing the soft hum of Christmas music (and maybe crunching some fresh snow off my boots if we’re lucky!), pulling this casserole from the fridge, and letting that festive aroma fill the house. Food just has a way of making memories feel extra special, especially when it’s warm, easy, and meant to be shared by the ones you love most.
So if you’re looking for something craveable and stress-free to start your Christmas (or honestly, any chilly morning that needs a little comfort), give this casserole a try. It really is like a warm hug in a baking dish!
Why You’ll Love It
- Make-ahead friendly—just assemble and let it chill overnight (big Christmas Eve win!)
- Hearty, melty, and sooo satisfying with that classic comfort food vibe
- Feeds a crowd, perfect for brunch or houseguests—no one’s left hungry
- Totally adaptable for picky eaters or clearing out the fridge
- Makes your whole house smell incredible—honestly, it’s half the magic
Key Ingredients
Ground Sausage: Go mild, hot, or even maple! Turkey sausage works well for a lighter version, or honestly—grab whatever’s on sale. I’ve even used plant-based crumbles on a couple “vegetarian” Christmases, and nobody complained (until I told them, ha!).
Bread: White bread is classic and soaks up the egg custard perfectly. But, I’ve totally used whole wheat, sourdough, or even that half-loaf of “almost too dry” hamburger buns. Toasted bread works best—it holds up and gives you those satisfying bites.
Cheese: Mild Cheddar is our go-to, but sharp Cheddar, Swiss, Pepper Jack—even a handful of leftover fancy cheese (looking at you, cheese board scraps) can work. You want something that melts well and tastes good to you.
Eggs & Milk: These are the glue! Whole milk gives the richest texture, but half-and-half brings it to “brunch at grandma’s” level. Skim works too, though it’s a bit lighter. And eggs—just the everyday kind.
Mustard Powder: It’s the secret “what’s-that?” ingredient. Just a tiny bit makes the casserole taste complete. No mustard powder? A little squirt of Dijon or a splash of Worcestershire gets you there in a pinch.
Complete list of ingredients with quantities and step-by-step instructions is just down below in the recipe card.
Step-by-Step Instructions
1. Prepare the Sausage
Crumble about a pound of your favorite sausage into a skillet (no need to be precise). Cook it over medium heat, stirring and breaking it up as you go, until it’s nice and browned with those irresistible crispy bits—no pink left! You’ll want to taste-test a bite, trust me.
Carefully drain off any extra fat—just spoon it out or tip the pan into a bowl lined with a paper towel. A little fat is good, but too much makes the whole thing, well… greasy. No soggy bottoms on my watch!
2. Mix the Egg Mixture
In a medium bowl, whisk together 4 large eggs, 2 cups whole milk, 1 teaspoon mustard powder, and 1/2 teaspoon kosher salt. Give it a good whisk so the eggs are nice and frothy. If you like a little black pepper, now’s your moment to add a few grinds.
Stir in all your cooked sausage and add about 6 slices of toasted bread, cut into cubes. (Seriously, toasting makes all the difference for texture!) Mix so every bread chunk gets a good soak in the custard—kind of like giving it a little bath.
Now, gently fold in a cup of shredded cheese. You want cheese in every bite but not so much that it turns into a cheese block—unless you’re into that, in which case, live your best life.
3. Assemble the Casserole
Lightly grease a 9×13-inch baking dish—a swipe of butter or even nonstick spray works. Easy cleanup = happy holiday.
Pour your sausage, bread, and egg mixture into the pan. Give everything a gentle smoosh with your spatula so it’s tucked in evenly. Don’t worry if it looks “rustic”—it’ll all bake up beautifully.
Cover tightly with foil or plastic wrap and refrigerate for at least 8 hours (overnight is ideal). This lets the bread soak up every bit of flavor, makes your morning way easier, and gives you an excuse for a second glass of Christmas Eve wine.
4. Bake the Casserole
When you’re ready (pajamas encouraged!), preheat the oven to 350°F. Uncover the casserole and pop it in the oven.
Bake, covered, for 45–60 minutes until the top is puffed and starting to turn golden around the edges. If it’s not quite set in the middle, drop the oven temp to 325°F and bake, uncovered, for another 30 minutes—edges should get a bit crisp and the inside should firm up.
Check doneness by sliding a knife or toothpick into the center. It should come out mostly clean—or with a little gooey cheese, but definitely not wet custard. Let it go a little longer if it looks runny; every oven’s a little different!
5. Serve and Enjoy
Let the casserole sit for at least 5 minutes before slicing—it’ll hold its shape much better (and you won’t burn your mouth with molten cheese, not that I’ve ever done that…). Cut into hearty squares and serve warm. If you’re feeling fancy, pair with fresh fruit salad, a dollop of sour cream, or crispy hash browns. Seconds (or thirds) totally encouraged!
Serving Suggestions
- Fruit salad: Something tart and juicy, like orange segments, grapes, or even pomegranate seeds, is perfect alongside all that savory richness.
- Hash browns: Whether you go homemade or frozen, they’re always a hit—especially with hungry teens and breakfast lovers.
- Drinks: Coffee, cocoa, orange juice, or honestly… a little bit of bubbly if you’re in celebration mode. You’ve earned it!
- Toppings: Scallions, parsley, hot sauce, or ketchup for the kids (it’s basically the law in my house).
Storage and Meal Prep Tips
This casserole is practically designed for busy holiday mornings. Assemble it the night before, cover, chill, and bake straight from the fridge. Warm breakfast with zero fuss!
Leftovers keep beautifully—pop slices in an airtight container and refrigerate up to four days. They reheat like a dream in the microwave (30–60 seconds) or in a hot oven for a crispier top. Perfect for quick weekday breakfast or late-night snack attacks.
Want to freeze? Absolutely! Either freeze the whole (unbaked) casserole tightly wrapped, or individual baked squares. Thaw overnight in the fridge, then reheat in the oven at 350°F until hot in the middle. It’s a lifesaver when guests drop by or you just need a breakfast treat in January.
Variations
- Vegetarian: Skip the sausage and load up on sautéed veggies like spinach, mushrooms, peppers, onion—whatever’s looking sad in the crisper. Plant-based sausage crumbles work great too.
- Spicy: Use hot sausage, Pepper Jack cheese, and a sprinkling of jalapeños. I always sneak in a squirt of hot sauce on my piece—I like a little wake-up call!
- Gluten-Free: Swap regular bread for your favorite gluten-free brand, or use cooked potatoes for a fun twist. (Tater tots are surprisingly excellent!)
- Cheese Lover’s: Add extra cheese on top before baking, or broil for the last 5 minutes for the bubbliest, crispiest crust.
- Mini Casseroles: Divide among ramekins for cute, personal servings—so fun for Christmas breakfast or a special brunch.
Final Note
There’s just something about a warm, savory breakfast casserole on a chilly holiday morning that makes everything feel a little bit more magical. Whether you mix it up every year or stubbornly stick to your “tried and true,” this recipe delivers cozy, crowd-pleasing flavor and enough leftovers for whoever decides to stay in pajamas ‘til noon.
If you give it a go—or add your own twist—I’d absolutely love to hear how it turned out or what made your celebration brighter. Drop a comment or a question below, and let’s swap some holiday kitchen stories! Wishing you full bellies, lots of laughter, and a kitchen that smells like pure joy.
Christmas Breakfast Casserole
Ingredients
- 1 lb ground sausage
- 1 tsp mustard powder
- 0.5 tsp kosher salt
- 4 large eggs beaten
- 2 cups whole milk
- 6 slices white bread toasted and cut into cubes
- 1 cup mild Cheddar cheese shredded
Instructions
- Crumble ground sausage into a medium skillet and cook over medium heat for 7–10 minutes, stirring occasionally, until fully browned. Drain excess fat and set aside.
- In a medium bowl, whisk together beaten eggs, whole milk, mustard powder, and kosher salt. Stir in the cooked sausage and toasted bread cubes. Mix gently to coat. Add shredded Cheddar cheese and stir to combine.
- Lightly grease a 9×13-inch baking dish. Pour the sausage, bread, and egg mixture into the dish, spreading it evenly. Cover and refrigerate for at least 8 hours or overnight.
- Preheat the oven to 350°F (175°C). Bake the casserole, covered, for 45–60 minutes until the top begins to set and turn golden brown. Reduce the heat to 325°F (163°C) and bake uncovered for another 30 minutes. Check for doneness with a knife inserted in the center—it should come out clean.
- Let the casserole cool for 5 minutes before slicing. Serve warm, garnished with optional sides like fresh fruit salad or hash browns for a complete meal.
