Overnight Breakfast Casserole

This Overnight Breakfast Casserole is a classic make-ahead dish filled with savory sausage, eggs, and cheese. It’s the perfect way for the entire family to start the day by filling up your stomach with this hearty casserole. You can’t help but come back for seconds of this flavorful, easy recipe!

My favorite meal of the day is breakfast. I honestly could eat breakfast foods any time of the day.

This is a great recipe to make for Christmas breakfast, or if you’re hosting family or friends overnight and need something to feed a crowd the next morning. It’s really easy and everyone will absolutely love it.
I know because my family certainly does!

What ingredients go in this easy Breakfast Casserole?

The best part of a delicious egg casserole is a loaf of good crusty bread. You want something with a nice crust, but that is soft inside to soak up all that eggy goodness overnight. I recommend French bread, but any crusty bread will work, and it’s best if it’s a day old because it will soak up the custard better if it’s just a tad bit stale.

You will also need the following:

• Melted butter
• Breakfast sausage, cooked and crumbled
• Shredded white cheddar cheese
• Shredded Swiss cheese
• 8 eggs
• Whole milk
• Dijon mustard
• Paprika
• Dry white wine – can substitute with apple cider vinegar, chicken broth or apple juice.

How to make Overnight Breakfast Casserole

This easy breakfast dish comes together in just a few steps.

First, prepare your baking dish by spraying a 9×13 casserole dish with cooking spray. Cut your loaf of bread into 1-inch cubes and spread them in a single layer over the bottom of the dish. Drizzle melted butter over the top of the bread.

Cook your sausage, crumbling as you go until there is no pink left. Sprinkle the sausage and cheese over the bread in the dish, spreading evenly.

In a separate large bowl, whisk together the eggs, whole milk, dijon mustard, paprika, and white wine. Pour this egg mixture over the casserole and cover it tightly with aluminum foil. Refrigerate this overnight.

In the morning, preheat your oven to 325 degrees F. While the oven heats, remove your casserole from the fridge and let it sit for about 20 minutes. Keeping the dish covered, bake it for 60-75 minutes or until the egg middle is just set and the edges are light golden brown.

If you like a bit more crispy texture, cook a bit longer until the egg is firmer and the edges are a bit darker brown.

Serve with gravy, maple syrup, or your favorite condiment. Or, just enjoy it as is!

Why do you have to make this recipe the night before? 

Breakfast casserole is so good because the small chunks of bread slowly soak up the eggy custard you make over several hours. If you don’t let it sit overnight and try to make it and bake it all at once, you’ll just have dry bread and cooked eggs– not very enjoyable.

Flavor Variations

You can change up some of the ingredients to customize this egg breakfast casserole to your own tastes.

• Add onion, garlic powder, herbs, or spices to increase or change the flavor profile. I like sage with my breakfast sausage. 
• Throw in some vegetables for flavor and health. Try diced red peppers or green peppers, or add in a handful of chopped spinach.
• Use chorizo instead of sausage and add some diced green chiles for a spicier taste, and serve with some salsa.
• Use your favorite cheese in place of the white cheddar and Swiss. Colby Jack is a favorite, as is sharp cheddar cheese.  

Storing Leftover Overnight Breakfast Casserole

Store any leftovers you have by covering them tightly with plastic wrap or placing them in an airtight container in the fridge. My baking dish has a lid, which I love, so I just pop it on and slide it into the refrigerator. When it’s time to reheat, allow the casserole to come to room temperature, then cover and bake it at 350 degrees F until heated through.

What to serve with this savory dish

While this breakfast recipe is certainly hearty enough on its own, my favorite thing to do is serve this simple casserole with some mixed fruit and some cinnamon rolls. That way everyone gets something a little sweet and a little savory. It’s also nice on busy mornings to just pop this in the oven while everyone is getting ready and serving it on its own.

Delicious Breakfast Recipes

You’ll find all sorts of tasty breakfast recipes on the breakfast category page. Whether you like something sweet for breakfast or something savory, we’ve got you covered.

• Do you love scones? You have to try these Cranberry Orange Scones, or if you’re a chocolate fan, try these Chocolate Chip Cream Scones.
• Maybe you’re a muffin fan instead! These Blueberry Muffins are so soft and delicious! Or, try these Lemon Poppy Seed Muffins for a tangy treat. 
• You savory breakfast people will die over this recipe for Caramelized Onion, Bacon, and Gruyere Quiche. It’s so good. Or try this Bacon, Onion, Mushroom, and Sage Frittata.

This recipe was originally published December 31, 2015. It has been updated in format and with pictures on September 7, 2023.