Make-Ahead Christmas Breakfast Casserole

This make-ahead Christmas breakfast casserole is the dish that gets you out of the kitchen and into the living room on a busy holiday morning. Savory sausage, melted cheddar, and soft custardy bread come together in one baking dish, with almost all the work done the night before.

All you do Christmas morning is slide it into the oven and let it bake while you open presents or pour coffee. It comes out puffed and golden, ready to feed a crowd without a single last-minute scramble.

Why This Casserole Wins Christmas Morning

I keep coming back to this recipe because it takes the pressure off of holiday breakfasts. Assemble everything the evening before, stash it in the fridge, and the next day you only have to preheat the oven and wait for the timer. That means you can actually sit down with a mug of coffee while it bakes.

The layers of tender bread, browned sausage, and sharp cheddar soak up a simple egg custard overnight. What you get is a slice that is soft in the center with crisp edges on top, and every forkful has a little sausage, a little cheese. It tastes like the kind of breakfast you want on a slow morning, even though you barely did anything that day.

Ingredients

• 1 lb breakfast sausage: bulk pork sausage, mild or spicy, removed from casings if needed
• ½ cup diced red bell pepper: for a little sweetness and holiday color
• 6 cups cubed French bread: cut into 1-inch pieces, slightly stale bread works best
• 8 large eggs
• 2 cups whole milk
• 2 cups shredded sharp cheddar cheese: divided, for layering and the top
• 1 tsp dry mustard powder
• ½ tsp kosher salt
• ¼ tsp black pepper
• 1 tbsp unsalted butter, softened: for greasing the dish
• ¼ cup sliced green onions: for serving

Variations / Substitutions

• Swap the sausage: browned diced bacon, cubed ham, or crumbled chorizo all work. Drain excess fat so the casserole does not get greasy.
• Use a different cheese: pepper jack adds heat, smoked gouda brings a mellow deep note, or a mix of mozzarella and parmesan creates a milder, stretchy top.
• Change the bread: sourdough, challah, or torn croissants soak up the custard beautifully. Avoid soft pre-sliced sandwich bread, which can turn to mush.
• Go vegetarian: skip the meat and sauté 8 oz sliced mushrooms with the bell pepper, adding a pinch of smoked paprika for depth.
• Add a little heat: diced jalapeño or a few dashes of hot sauce in the egg mixture wakes everything up.

If you are after a sweeter holiday morning, our Gingerbread Pancakes are another favorite.

How to Make Christmas Breakfast Casserole

Step 1: Brown the Sausage and Peppers

Place a large skillet over medium heat and add the 1 lb breakfast sausage. Cook, breaking it up with a wooden spoon, until no pink remains, about 6 to 8 minutes. Stir in the ½ cup diced red bell pepper during the final 2 minutes, just until the pepper softens a little and the sausage is fully browned.

Drain off any excess fat, then remove the pan from the heat and let the mixture cool slightly. The kitchen will smell like sizzling sausage and sweet peppers, which is your first hint of what is coming.

Step 2: Whisk the Custard

Crack the 8 eggs into a large bowl and pour in the 2 cups whole milk. Add the dry mustard, salt, and black pepper. Whisk until the eggs are completely blended and the mixture looks pale yellow with no streaks of white left.

This part comes together in less than a minute. You want the mustard powder fully dissolved so you do not get little bitter pockets later.

Step 3: Assemble the Casserole

Use the softened butter to grease a 9×13 inch baking dish. Scatter half of the cubed French bread across the bottom, then top with half of the cooked sausage mixture and 1 cup of the shredded cheddar. Repeat with the remaining bread, sausage, and the other cup of cheese. Slowly pour the egg mixture evenly over the top, aiming to cover all the bread pieces.

Press down gently with a spatula so every cube has a chance to soak. You will see the bread start to absorb the custard right away, which is exactly what you want. Cover tightly with plastic wrap or foil and refrigerate for at least 4 hours, but overnight is the goal.

Step 4: Bake Until Golden

When you are ready to bake, preheat the oven to 350°F (175°C). Uncover the dish and let it sit on the counter while the oven heats, about 20 minutes, to take the deep chill off. Bake on the center rack for 45 to 55 minutes. The casserole is done when a knife inserted near the center comes out clean and the top is puffed and golden brown with darker cheesy spots.

If the top is browning too fast before the center sets, lay a piece of foil loosely over it and continue baking. The whole kitchen will smell like toasted cheese and sausage, and the edges will be crisp and pulling away from the dish slightly.

Step 5: Slice and Serve

Let the casserole rest for 10 minutes on the counter once it comes out of the oven. This short wait helps the slices hold together when you cut them. Run a knife around the edge, then cut into squares and lift them out with a spatula.

Scatter the sliced green onions across the top and serve the squares warm. The inside will be custardy and soft, while the top stays a little crunchy from the cheese.

A Few Notes Before You Start

• Give it time to soak.: Four hours is the absolute minimum. Overnight is better because it lets the bread fully absorb the custard so every bite tastes rich, not eggy.
• Use day-old bread if you can.: Slightly stale bread holds its shape better and soaks up more liquid without going gummy. If your bread is fresh, spread the cubes on a sheet pan and toast at 300°F for 10 minutes first.
• Check doneness carefully.: The center should reach 160°F (71°C) on an instant-read thermometer, or a thin knife should come out clean. If it wiggles like raw custard in the middle, give it more time.
• Prep the sausage the day before.: Browning the meat ahead saves a step on assembly night. Store it in the fridge and use it straight from cold when you layer the casserole.

Bake times by pan size or amount:

Storing Leftovers

• Refrigerate: Cover leftover casserole tightly and store in the fridge for up to 4 days. It reheats well and makes a great quick breakfast on busy mornings.
• Reheating: Warm individual slices in the microwave for 60 to 90 seconds, or place in a 325°F oven for 10 to 12 minutes until heated through. The oven gives you back some of the crisp top.

What To Serve With Christmas Breakfast Casserole

A big bowl of fresh fruit salad cuts through the richness and adds something bright to the plate. For drinks, cold orange juice or hot coffee are natural partners. If you want a little celebration, a mimosa (equal parts orange juice and cold sparkling wine) balances the savory cheddar and sausage without being too heavy.

Frequently Asked Questions

Can I bake this casserole right away without the overnight soak?

Yes, but let the assembled dish rest for at least 30 minutes so the bread has a chance to drink up some of the custard. The texture will be a little looser and the slices may not hold together as neatly as the overnight version.

Can I make it with gluten-free bread?

Yes. Use a sturdy gluten-free loaf that does not crumble easily when wet. Let the dish soak overnight as directed, because gluten-free bread usually needs more time to soften fully.

Can I freeze the casserole?

Yes. Assemble the casserole in a freezer-safe dish, cover tightly, and freeze for up to 1 month. Thaw completely in the refrigerator overnight, then bake as directed, adding 5 to 10 extra minutes if needed.

Can I leave out the sausage?

You can. Replace it with 2 cups of sautéed mushrooms and an extra ½ cup of bell pepper. A pinch of smoked paprika in the egg mixture helps bring back some of the savory depth the sausage normally gives.

Christmas Breakfast Casserole Recipe

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Prep Time 25 minutes mins

Cook Time 55 minutes mins

Total Time 1 hour hr 20 minutes mins

Servings: 8 servings

Calories: 410

Ingredients Method Notes

Ingredients

  

• 1 lb breakfast sausage
• ½ cup diced red bell pepper
• 6 cups cubed French bread
• 8 large eggs
• 2 cups whole milk
• 2 cups shredded sharp cheddar cheese
• 1 tsp dry mustard powder
• ½ tsp kosher salt
• ¼ tsp black pepper
• 1 tbsp unsalted butter, softened
• ¼ cup sliced green onions

Method

 

1. Brown the sausage in a skillet over medium heat, breaking it up, until no longer pink, 6 to 8 minutes. Add the bell pepper during the last 2 minutes, then drain excess fat.
2. Whisk together the eggs, milk, mustard, salt, and pepper in a large bowl until smooth.
3. Grease a 9×13 inch baking dish with butter. Layer half the bread, half the sausage mixture, and 1 cup cheddar. Repeat layers, then pour the egg mixture evenly over the top. Press down gently, cover, and refrigerate at least 4 hours or overnight.
4. Preheat the oven to 350°F. Uncover the dish and let it stand 20 minutes while the oven heats. Bake 45 to 55 minutes, until puffed, golden, and a knife inserted near the center comes out clean.
5. Let the casserole rest 10 minutes, then slice into squares and serve warm with green onions scattered on top.

Notes

The prep time covers the hands-on work for browning the sausage and assembling the dish. The overnight soak is not included in the total time, so plan to start the night before for the best result. If your dish is deep, lean toward the longer bake time and cover with foil if the top gets dark too quickly.