Christmas morning hits different.
Kids (or dogs, let’s be honest) are vibrating with excitement, the tree lights are glowing, coffee’s brewing, and nobody—nobody—wants to stand over a stove flipping pancakes while the chaos unfolds.
That’s why, for the last fifteen years, this overnight sausage-egg-cheese casserole has been my absolute ride-or-die.
It’s the one dish that lets you stumble downstairs in pajamas, slide something golden and bubbling out of the fridge-to-oven, and twenty minutes later you’re passing out plates of pure holiday comfort while the wrapping paper flies.
Trust me, I’ve tested every version under the sun. This one wins. Every single time.
It’s rich but not heavy, feeds a crowd without breaking the bank, and—most importantly—tastes even better when you assemble it the night before, half-asleep and still holding a glass of wine.
Let’s make the best Christmas morning breakfast casserole you’ll ever eat.
Ingredients & Substitutions
Here’s exactly what you need for a 9×13 pan that feeds 8–10 very happy people.
| Ingredient | Amount (Imperial) | Amount (Metric) | Notes & Best Substitutions |
|---|---|---|---|
| Day-old bread | 10–12 cups cubed | 500–600 g | Sourdough, brioche, or challah. Gluten-free bread works 1:1 |
| Breakfast sausage | 1 lb / 450 g | Mild or hot Italian, turkey sausage, or plant-based crumble | |
| Sharp cheddar, shredded | 3 cups / 12 oz | 340 g | Extra-sharp for punch, or half cheddar/half gruyère if you’re fancy |
| Eggs | 10 large | Duck eggs make it extra luxe | |
| Whole milk | 2½ cups / 600 ml | 2% works, but whole gives the silkiest texture | |
| Heavy cream | 1½ cups / 360 ml | Half-and-half is fine, coconut cream for dairy-free | |
| Dijon mustard | 2 tablespoons | Don’t skip—brightens everything | |
| Kosher salt | 1 teaspoon | Plus more for seasoning sausage | |
| Fresh ground black pepper | ½ teaspoon | ||
| Garlic powder | ½ teaspoon | Fresh minced garlic burns; powder is better here | |
| Onion powder | ½ teaspoon | ||
| Fresh scallions, sliced | ½ cup | Or chives | |
| Fresh parsley, chopped | ¼ cup | Totally optional but pretty |
Ingredient geek-out moment:
Use day-old bread because fresh bread turns to mush. Stale cubes soak up the custard without disintegrating.
Sharp cheddar melts smooth and gives that nostalgic “church-potluck” vibe. Pre-shredded is convenient but coated in anti-caking starch—grate your own if you can.
Dijon is the secret weapon. It doesn’t scream mustard; it just wakes everything up.
Dairy-free? Use oat milk + coconut cream combo and vegan cheese that actually melts (Violife mature cheddar is shockingly good).
Vegetarian? Swap sausage for roasted mushrooms + spinach or those Impossible sausage patties. Still incredible.
Step-by-Step Instructions
Do this the night before. Your future self will send you flowers.
- Grab your biggest skillet. Medium-high heat. Crumble the sausage in—no need to add oil, it’ll render plenty. Cook till deeply browned, breaking it into small bits. You want crunchy edges. Takes about 8–10 minutes. Scoop it out, leave a couple tablespoons fat in the pan.
- While the sausage cools, cube the bread into roughly 1-inch pieces. Toss them into a buttered 9×13 dish. Spread evenly.
- Scatter the cooked sausage over the bread. Then half the cheese. Then the scallions.
- Whisk eggs in a big bowl like you mean it—30 seconds till frothy. Add milk, cream, Dijon, salt, pepper, garlic powder, onion powder. Whisk again. Pour this custard slowly over the bread, making sure every cube gets some love. Press down gently with a spatula so everything’s submerged.
- Top with remaining cheese. Cover tight with foil or plastic wrap. Fridge it overnight—minimum 6 hours, up to 24.
- Christmas morning: Preheat oven to 350°F / 175°C. Leave the foil on for the first 30 minutes (this steams it gently). Then remove foil, bake another 20–30 minutes till puffed, golden, and set in the center. A knife inserted should come out clean, no wet custard.
- Rest 10 minutes. It’ll deflate a little—that’s normal. Sprinkle fresh parsley. Cut into squares and watch people lose their minds.
Pro moves:
If the top browns too fast, tent loosely with foil.
Undercooking is the #1 killer—don’t pull it early just because it looks pretty. Give it the full time.
Cooking Techniques & Science (The Nerdy Stuff I Love)
Overnight soaking is pure genius. The bread absorbs custard slowly, creating that creamy-strata-meets-French-toast texture. Science calls it retrogradation—basically, stale bread rehydrates without falling apart. Fresh bread would dissolve into sad mush.
The foil-on, foil-off method? Steams first for tenderness, then crisps the top. Restaurant trick.
Cheese on top creates that lacquered, pull-apart crust. Cheese in the middle melts into pockets of joy. Two layers = non-negotiable.
And the Maillard reaction on the sausage? That’s where deep savory flavor lives. Pale sausage = bland casserole. Don’t rob yourself.
You don’t need fancy tools. A $20 glass Pyrex dish works as well as the $120 ceramic one. Promise.
Storage, Reheating & Make-Ahead Magic
Assembled casserole keeps 24 hours in the fridge, uncooked. After that, bread gets too soggy.
Baked leftovers? Airtight container, fridge up to 4 days. They actually taste better day two—the flavors marry.
Reheat individual squares in the air fryer at 350°F for 5–6 minutes—crisp top, creamy middle. Or oven at 325°F covered with foil 15–20 minutes. Microwave works in a pinch but you lose the crispy edges.
Freezing: Bake first, cool completely, portion into squares, freeze solid, then bag. Reheat from frozen in 350°F oven 25–30 minutes. Still delicious.
Variations That Slay
Southwest Christmas: Use chorizo, pepper jack, add roasted green chiles and a spoon of adobo sauce in the custard. Top with salsa and avocado morning-of.
Fancy Brunch: Swap sausage for crispy prosciutto or smoked salmon, add leeks sautéed in butter, finish with dill and lemon zest.
Veggie Lover: Roasted butternut squash, sage, goat cheese crumbles, and a splash of maple in the custard. Autumn on a plate.
French Onion Vibes: Caramelize 3 big onions low and slow, use gruyère, add a teaspoon of fresh thyme. Insanely good.
Low-Carb/Keto: Skip bread entirely, double the eggs, add spinach and feta. Bake in muffin tins for grab-and-go portions.
Serving & Pairing Suggestions
Cut into big squares and serve straight from the dish—family style feels right on Christmas morning.
Garnish ideas: Extra scallions, dollop of sour cream, hot sauce on the side, or a shower of everything-bagel seasoning right before serving.
Pairings that make it a full spread:
- Fresh orange segments or cranberry-orange salad for brightness
- Crispy bacon or maple sausage links (because more pork never hurts)
- Strong coffee, obviously
- Sparkling mimosa bar—OJ, cranberry juice, prosecco. Let people mix their own.
- Soft dinner rolls if you want to sop up extra custard
When This Casserole Shines Brightest
Christmas morning, obviously. But also Easter brunch, baby showers, potlucks, the morning after hosting friends—anytime you want to feed a lot of people with zero stress.
It’s winter comfort food, but I’ve served it on the porch in July with cold brew and zero regrets. Food doesn’t care about seasons when it’s this good.
Final Love Note
This casserole isn’t just food. It’s permission to slow down, to gather, to let the oven do the heavy lifting while you sip coffee and watch little faces light up. It’s the smell that drifts through the house and makes memories stick.
Make it once, you’ll make it every year. That’s not marketing. That’s just truth.
FAQs
Can I make this without overnight soaking?
You can, but give it at least 2 hours in the fridge. Texture won’t be quite as silky, but it’ll still be delicious in a pinch.
My custard looks separated or curdled—did I ruin it?
Nah. Sometimes cold dairy + eggs look a little broken when you first mix. Whisk hard, it’ll come together in the oven.
Can I use all milk and skip the cream?
Yes, but it’ll be slightly less rich. Bump the cheese a bit to compensate.
Help—my casserole is watery on the bottom!
Two culprits: fresh (not stale) bread, or you didn’t bake long enough. Next time, stale bread + full bake time till center is set.
Is it weird to add a splash of hot sauce to the custard?
Not weird. Genius. Do it. Frank’s or Cholula, about a teaspoon. Wakes everything up without making it “spicy.”
Now go tear up some bread, brown some sausage, and get ready for the best Christmas morning of your life. You got this.
