Make-Ahead Christmas Morning Magic: Overnight Breakfast Casserole

Key Takeaways:

• Prep this savory breakfast casserole on Christmas Eve for a stress-free holiday morning
• Perfect for 4 people with just 15 minutes of prep time
• Customize with your favorite breakfast meats and cheeses
• Stores well for up to 3 days for post-holiday leftovers

Why You Need This Overnight Breakfast Christmas Casserole

Ever feel overwhelmed on Christmas morning? Between opening presents and keeping up with holiday traditions, cooking a hot breakfast can feel impossible. That’s where this overnight breakfast Christmas casserole comes in!

I’ve created this recipe specifically for families of four who want a special breakfast without the Christmas morning chaos. This make-ahead miracle lets you enjoy the holiday moments that matter most.

Nutrition Facts

Nutrient	Amount per Serving
Calories	425
Protein	22g
Carbohydrates	28g
Fat	24g
Fiber	2g
Sodium	820mg
Sugar	4g

Serving size: 1/4 of casserole

What You’ll Need

Ingredients

Ingredient	Amount
White bread, cubed	6 cups (about 8 slices)
Breakfast sausage	1 pound
Cheddar cheese, shredded	1 1/2 cups
Eggs	8 large
Milk	2 cups
Dijon mustard	1 tablespoon
Salt	1 teaspoon
Black pepper	1/2 teaspoon
Dried herbs (thyme, rosemary, or sage)	1 teaspoon
Butter (for greasing dish)	2 tablespoons

Kitchen Equipment

Tool	Purpose
9×13-inch baking dish	Main cooking vessel
Large skillet	Cooking sausage
Mixing bowl	Combining egg mixture
Whisk	Beating eggs
Measuring cups and spoons	Measuring ingredients
Cutting board	Preparing bread
Knife	Cutting bread
Aluminum foil	Covering casserole

Possible Substitutions

• Bread Options: Use leftover bread, French bread, or even dinner rolls instead of white bread
• Meat Choices: Substitute cooked bacon or ham for the sausage
• Cheese Varieties: Try pepperjack cheese for a spicy kick or Swiss for a milder flavor
• Dietary Adjustments: Use dairy-free milk and cheese for lactose intolerance

Detailed Step-by-Step Instructions for Beginners

Preparation (Christmas Eve)

Prep Time: 15 minutes

Step 1: Gather Your Ingredients and Tools

1. Take out all ingredients from the refrigerator and pantry
2. Measure everything in advance using measuring cups and spoons
3. Place all measured ingredients in small bowls or on a plate
4. Make sure your 9×13-inch baking dish is clean and dry
5. Check that you have aluminum foil ready for covering the casserole

Step 2: Prepare Your Baking Dish

1. Unwrap the butter and let it soften for a few minutes
2. Take 2 tablespoons of butter and place it in your baking dish
3. Using your fingers or a paper towel, spread the butter all over the bottom of the dish
4. Don’t forget to butter the sides and corners thoroughly
5. Set the greased dish aside on your counter

Step 3: Prepare the Bread

1. Place a slice of white bread on your cutting board
2. Using a serrated knife, cut the bread into 1-inch squares (about 4 cuts horizontally and 4 cuts vertically)
3. Transfer the bread cubes to a bowl
4. Repeat with the remaining 7 slices of bread
5. Gently pour all bread cubes into your buttered baking dish
6. Spread them out evenly with your hands or a spoon

Step 4: Cook the Breakfast Sausage

1. Place your large skillet on the stove
2. Turn the heat to medium (usually around the 5 setting on most stoves)
3. Allow the pan to heat up for 1-2 minutes
4. Unwrap the package of breakfast sausage
5. Drop the sausage into the heated pan
6. Using a wooden spoon or spatula, break the sausage into small crumbles
7. Stir occasionally for 7-8 minutes until all pieces are browned
8. The sausage is done when no pink remains and it reaches 160°F on a meat thermometer
9. Turn off the heat
10. Line a plate with 2-3 paper towels
11. Using a slotted spoon, transfer the cooked sausage to the paper towel-lined plate
12. Let the sausage cool for 5 minutes (this prevents it from making the bread soggy)

Step 5: Assemble the Base Layers

1. Once the sausage has cooled slightly, sprinkle it evenly over the bread cubes
2. Make sure to distribute it throughout the dish, not just on top
3. Open the package of shredded cheddar cheese (or shred your own using a cheese grater)
4. Measure out 1 1/2 cups of cheese
5. Sprinkle the cheese evenly over the sausage and bread
6. Use your fingers to lightly toss the layers if needed for even distribution

Step 6: Make the Egg Mixture

1. Crack 8 eggs one at a time into a large mixing bowl

• Tap each egg gently on the counter
• Hold the egg over your bowl and pull apart the shell with both thumbs
• Let the egg drop into the bowl
• Check for and remove any shell pieces with a spoon

1. Add 2 cups of milk to the eggs
2. Add 1 tablespoon of Dijon mustard
3. Measure and add 1 teaspoon salt
4. Measure and add 1/2 teaspoon black pepper
5. Measure and add 1 teaspoon of your chosen dried herbs
6. Take a whisk and beat everything together:

• Hold the bowl with one hand to keep it steady
• Use a circular motion with the whisk until everything is well mixed
• The mixture should be an even yellow color with no streaks
• This usually takes about 30-45 seconds of whisking

Step 7: Combine Everything

1. Slowly pour the egg mixture over the bread, sausage, and cheese layers
2. Start pouring around the edges, then move toward the center
3. Go slowly to allow the liquid to soak in
4. If needed, use the back of a spoon to gently press down on the bread cubes
5. Make sure all bread pieces are moistened by the egg mixture
6. Tilt the dish slightly if there are any dry spots to move the liquid
7. Tear off a piece of aluminum foil large enough to cover your dish
8. Press the foil tightly around the edges of the baking dish to create a seal
9. If your foil isn’t wide enough, use two pieces and fold them together in the middle

Step 8: Refrigerate Overnight

1. Make sure your refrigerator has a flat, clear space on a shelf
2. Carefully lift the covered casserole with both hands
3. Place it on the refrigerator shelf where it won’t be disturbed
4. Close the refrigerator door
5. Let the casserole sit for at least 8 hours or overnight (up to 24 hours is fine)
6. This resting time is important – it allows the bread to fully absorb the egg mixture

Baking (Christmas Morning)

Cook Time: 45-55 minutes

Step 9: Prepare for Baking

1. Take the casserole out of the refrigerator
2. Place it on the counter to sit at room temperature
3. Turn on your oven to preheat at 350°F (175°C)
4. Allow the casserole to rest for about 30 minutes while the oven preheats
5. This helps the dish warm up slightly so it will cook more evenly

Step 10: Start Baking

1. Make sure your oven rack is in the center position
2. Once the oven is fully preheated (most ovens will beep or light up when ready)
3. Carefully place the covered casserole in the oven
4. Close the oven door gently
5. Set a timer for 30 minutes
6. Don’t open the oven during this time to maintain temperature

Step 11: Finish Baking

1. When the timer goes off after 30 minutes, open the oven door
2. Carefully remove the foil from the casserole

• Pull the foil toward you first to allow the steam to escape away from your face
• Use oven mitts to protect your hands

1. Close the oven door
2. Reset the timer for 15 minutes
3. After 15 minutes, check if the casserole is done:

• The top should be golden brown
• The center should be set and not jiggly
• You can insert a knife in the center – it should come out clean

1. If not fully cooked, return to oven for an additional 5-10 minutes
2. Watch closely during this time to prevent over-browning

Step 12: Rest and Serve

1. When fully cooked, remove the casserole from the oven using oven mitts
2. Place it on a heat-safe surface like a cooling rack or trivets
3. Let the casserole rest for 10 minutes

• This allows it to set up for easier cutting
• The internal temperature will still be hot for serving

1. Cut the casserole into four equal portions
2. Use a spatula to lift each portion onto plates
3. Serve while still warm

Troubleshooting

Problem	Solution
Casserole is too dry	Add an extra 1/2 cup of milk to the egg mixture next time
Eggs not fully cooked	Bake for 5-10 minutes longer, covering with foil if top is getting too brown
Too much liquid	Make sure bread is slightly stale or toasted before using
Casserole stuck to dish	Be more generous with butter when greasing the dish
Uneven cooking	Rotate the dish halfway through baking time

Variations & Substitutions

Sweet Version

Transform this into a sweet French toast casserole by:

• Omitting sausage and savory seasonings
• Adding 1/4 cup sugar and 1 teaspoon cinnamon to the egg mixture
• Topping with a mixture of brown sugar and butter before baking

Vegetarian Option

• Replace sausage with 2 cups of sautéed vegetables (bell peppers, onions, spinach)
• Add 1/4 teaspoon garlic powder for extra flavor

Hash Brown Base

• Substitute 4 cups of shredded potatoes for the bread
• Increase baking time by 10-15 minutes

Storage & Reheating

Refrigerator Storage

• Cool completely before storing
• Cover leftovers tightly with plastic wrap or transfer to airtight containers
• Refrigerate for up to 3 days

Freezer Storage

• Cut cooled casserole into individual portions
• Wrap each piece in plastic wrap, then aluminum foil
• Freeze for up to 2 months
• Label with date and contents

Reheating Instructions

• Refrigerated leftovers: Microwave individual portions for 1-2 minutes or reheat in a 325°F oven for 15-20 minutes
• Frozen portions: Thaw overnight in refrigerator, then reheat as above, adding 5-10 minutes to heating time

Safety Notes & Tips

Food Safety

• Never leave the egg mixture at room temperature for more than 2 hours
• Ensure sausage reaches 160°F internal temperature when cooking
• Casserole should reach 165°F in the center when fully baked

Time-Saving Tips

• Use pre-cooked sausage crumbles to save prep time
• Prepare and cube bread a day ahead and leave out to get slightly stale
• Shred cheese yourself for better melting (pre-shredded has anti-caking agents)

Make It Special

• Serve with a side of fresh fruit for a complete breakfast
• Add a small bowl of maple syrup on the table for those who enjoy a sweet touch
• Garnish with fresh herbs just before serving for a festive look

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Prep time: 15 minutes | Cook time: 45-55 minutes | Overnight chilling: 8+ hours | Serves: 4

Perfect for: Christmas morning, holiday brunch, or any special breakfast when you want to enjoy the morning without cooking