Overnight Sausage Breakfast Casserole (easy!)

This easy overnight sausage breakfast casserole is the perfect make ahead breakfast entree. Simply prep the night before, refrigerate and bake the next morning. It's SO delicious and flavorful! It's the ideal option for your holiday breakfast table, brunch parties, breakfast potlucks, Mothers Day brunch and so much more!

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Overnight sausage breakfast casserole in a white square baking dish — This delicious overnight sausage breakfast casserole is all about convenience. Prepare it the night before to make tomorrow's breakfast as easy as preheating your oven and baking.

Breakfast casserole season is nearly upon us - that's December if you didn't know - and if you are looking for an easy and delicious holiday morning breakfast recipe, then we have this tasty overnight sausage breakfast casserole for you today!

Overnight breakfast casseroles are great for entertaining and convenience, and we have a few of those on the site to choose from, like this overnight sausage breakfast casserole, this vegetarian Tater Tot™ breakfast casserole, and this triple cheese breakfast casserole.

My friend Jana gave me this recipe and told me that this has been a popular holiday breakfast recipe at her house for years. This is the first year that we have been able to enjoy it at our house, and I must say that it is surely here to stay. It is scrumptious!

Table of Contents

❤️ Reasons to Love This Casserole
🥣 Equipment
🥚 Ingredients
📋Instructions (With Photos)
❓ Frequently Asked Questions
🍲 Related Recipes
Recipe
🕮 References and Further Reading
Comments

❤️ Reasons to Love This Casserole

It's convenient. The prep is super easy and to make it even more convenient, you can do the prep the night before. All that you have to do the next morning is preheat your oven and bake!
It's super flavorful. Beyond flavorful even. You just have to try it!
It's relatively healthy. It comes in at a little over 300 calories/serving and contains 19 grams of protein to keep you satisfied all morning.
It can be made ahead. This isn't just a holiday breakfast recipe or one to feed a brunch crowd, it's a great make-ahead recipe for everyday as well. We have a few ideas up our sleeve along this vein - like this ham and cheese frittata, leek and mushroom quiche, triple cheese breakfast casserole, quiche Provencale, and green chile breakfast casserole to name a few. They're all great make ahead, meal prep breakfast ideas!
It's high protein and low carb. This casserole contains 19 g protein, and that's important for sustained energy. That's awesome enough, but to make it even better, it contains only 7 g of carbs. That's great if you're on a low carb diet.
It's simple. It take just a few readily-available ingredients to make this fabulous breakfast casserole.

🥣 Equipment

This recipe uses the following equipment (affiliate links):

Skillet. For cooking and browning the sausage.
Large glass bowl. For mixing the egg mixture.
8-inch square ceramic baking dish. For baking and serving.

🥚 Ingredients

Ground breakfast sausage (½ pound). Breakfast sausage adds a lot of great flavor. To save time and make preparation even easier, you can chop up pre-cooked sausage links or patties or add prepared sausage crumbles. For a healthier version, use turkey or chicken sausage instead.
Large eggs (6). You can use the eggs straight from the refrigerator. No need to bring to room temperature first.
Milk (1 cup). You can use whole, 2%, 1%, or lactose-free. I used lactose-free milk. I have not tested this recipe with nut, soy or coconut milk.
White bread (2 slices). Cut into 1-inch cubes.
Cheddar cheese (1 cup), shredded. For convenience I used pre-shredded cheese. What type of cheddar cheese to use depends on your taste. Sharp has the most flavor, and that's what we wanted so that's what we used. You can try mild for a less tangy flavor or medium for something in between.
Yellow mustard (1 teaspoon). Most people have mustard in their fridge. You can use whatever you have. To substitute ground (powdered) mustard, reduce to ½ teaspoon.
Salt (¾ teaspoon). Adds flavor.
Chopped chives for garnish. This ingredient is optional.

📋Instructions (With Photos)

Breakfast sausage cooking in a skillet — **Step 1.** The night before serving, add sausage to a medium skillet over medium-high heat and cook until browned. Use a wooden spoon or spatula to stir and break up into smaller pieces. Continue cooking until browned. Set aside.

Egg mixture in a glass bowl with a whisk — **Step 2.** In a large mixing bowl, combine eggs, milk, mustard, and salt. Whisk thoroughly.

Breakfast sausage and cubed bread in a glass bowl with egg mixture — **Step 3.** Add cubed bread and cooked sausage to egg mixture. Stir until combined.

Raw sausage breakfast casserole in a square white baking dish — **Step 4.** Spray a 8" square baking dish with cooking spray and pour egg mixture in.

Shredded yellow cheddar cheese sprinkled on top of unbaked breakfast casserole — **Step 5.** Sprinkle the top with shredded cheddar cheese.

Step 6. Cover the casserole dish with plastic wrap and refrigerate overnight.

Step 7. The next morning, preheat oven to 325°F (176°C).

Remove cover from casserole and bake for 35-45 minutes until the top is lightly browned and a meat thermometer inserted in the center registers 160°F (71°C). Remove from oven and let cool for 5 minutes. Serve warm.

A serving spoon scooping out a serving of overnight sausage breakfast casserole — Not only is this breakfast casserole great for feeding a crowd, but it's an excellent option for everyday meal prep. Make it ahead on the weekend and portion it out for the week. The baked casserole will keep in your fridge for up to a week and in the freezer for up to 3 months.

Click here to learn how to make this overnight sausage breakfast casserole in a visual story.

❓ Frequently Asked Questions

How can I know when the breakfast casserole is done baking?

Your casserole is done baking when the internal temperature registers 160°F (71°C).
For food safety reasons, it is important to cook egg recipes to the proper temperature. The most reliable way to test for doneness is to use a meat thermometer. Insert the thermometer into the center of the casserole and leave it there until the needle stops moving. If the temperature is at least 160°F (71°C), you can remove the casserole from the oven. If it is below that temperature, remove the thermometer, and return the casserole to the oven to continue baking. Check again after five minutes. Repeat as necessary.

Can you freeze this overnight sausage breakfast casserole?

You can freeze any leftovers, but I don't recommend freezing the unbaked casserole because the bread cubes may break down and lose their texture when thawing.
To freeze leftovers, place them in a container designed for the freezer. Store for up to three months. You can reheat in the microwave. Start with 3-4 minutes on high. Check and adjust as necessary.

Can I use a different size baking dish?

If you do not have an 8-inch square baking dish or the one that you have is being used for something else, you can substitute a pan of similar size. For this recipe, you can use a 2-quart casserole dish, an 11x7-inch baking pan or a 9x5-inch loaf pan. The cooking time may need to be adjusted. Use the thermometer method mentioned in the first question above to test for doneness.

Serving of breakfast casserole on a green plate

Are you looking for more delicious recipes like this? You may also like:

For a low carb version, give this Low-Carb Southwest Egg Casserole from Kalyn's Kitchen a try!

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