How to Make Easy Overnight Breakfast Casserole (2024)

Learn how to make an easy overnight breakfast casserole for busy mornings. The ingredients are simple and the effort is minimal. Take the stress out of making a morning meal for guests. Read on for the easy recipe!

My Overnight Breakfast Casserole Backstory

Are things around your house a bit crazy on holiday mornings? Perhaps you have a houseful of guests. What if they are hungry? Here’s something you can do to make holiday mornings less chaotic and more enjoyable. I make this whenever we have a guests and for special holiday breakfasts. This delicious dish has made those mornings more enjoyable at our house. What is this marvelous concoction? It’s an easy overnight breakfast casserole (sometimes called a strata) with a spicy zing that will make your taste buds sit up and take notice. How easy is it? Read on to find out!

Can I Prepare a Casserole the Night Before?

Yes, the whole idea behind this casserole is to give you some extra time to relax in the morning. I’m a big fan of preparing things ahead of time, like my Make-Ahead Mashed Potatoes. Anything I can do to avoid a last-minute frenzy in the kitchen, I do it. Plan some time the night before to assemble this easy overnight breakfast casserole, then pop it in the refrigerator. This particular recipe bakes for 90 minutes. By the time it’s finished baking, everyone might be out of bed and ready to eat.

Ingredients

1 pound ground pork sausage

1 medium onion

2 boxes (or bags) cheddar cheese croutons (Seasoned and other varieties are okay as well.)

2 cups grated cheddar cheese

4 eggs

2 cups milk

1/2 teaspoon dry mustard

1 can cream of mushroom soup

1/2 cup salsa

Directions

Preheat the oven to 300 degrees. Grease a 9 by 13-inch casserole dish. Use the wrapper from a stick of butter, if you have one on hand. I store extra butter wrappers in a special spot in my refrigerator.

Chop the onion. Put the chopped onion and the sausage in a skillet. Brown the onions with the sausage and drain excess fat, if any.

Line the bottom of the casserole dish with croutons.

Layer sausage on top, then cover with cheese.

Beat eggs, milk, and mustard together in a bowl.

Pour over the top of the casserole. Refrigerate overnight or for 8 hours. Before baking, mix soup with 1/2 cup of salsa.

Smooth over the top of the casserole and bake for 1 and 1/2 hours or more until bubbly.

How Long Can Breakfast Casserole be Refrigerated Before Cooking?

For this recipe, a minimum of 8 hours in the refrigerator is good. As far as a maximum amount of time, you could fix this casserole 24 hours ahead if you wanted. The croutons in this recipe hold up well with additional time. Some recipes that call for softer bread might get a bit soggy if left for too long before baking.

Why Does Breakfast Casserole (Strata) Have to Sit Overnight?

The main reason this recipe needs to sit overnight is because the croutons need time to soak up the liquid and become softened. If you want to make this recipe for dinner, as I recently did, you could put it together in the morning and let it refrigerate all day. It makes a great dinner option, especially if you need to use up some eggs. Our chickens have been laying quite steadily lately, so we have quite a few eggs on hand. We appreciate our chickens!

Does Egg Casserole Need to be Refrigerated?

These FDA egg safety guidelines are very helpful. Eggs should be refrigerated whether in a casserole or in their carton. No one wants to get Salmonella (a common cause of food poisoning).

How do You Know When Egg Casserole is Done?

When the oven timer goes off, take a sharp knife and stick the tip into the casserole. If it comes out clean, the easy overnight breakfast casserole is done. If you placed the casserole directly into the oven from the refrigerator, you may have to add a few extra minutes of cooking time.

How do You Reheat Egg Casserole Without Overcooking?

My favorite way to reheat a breakfast casserole is to pop it into the microwave for about a minute. That’s what I do if I am just reheating it for myself. If I am reheating it to serve to others, I cover it with foil. I set the oven to 350 degrees and let the casserole reheat for about 30 minutes. If you want to have a crispy top, you could remove the foil. Turn the oven on to broil and let the casserole stay in the oven for a couple more minutes, uncovered.

How Long Can an Egg Casserole Sit Out?

Once again, according to the handy FDA guide, the easy overnight breakfast casserole should not sit out after baking for more than 2 hours. If you are eating the egg casserole in temperatures of 90 degrees or hotter, then the cooked casserole should not sit out longer than an hour. I’ve never eaten a breakfast casserole outdoors in hot weather, but it could happen.

How Long is Egg Casserole Good in the Fridge?

Any leftover cooked breakfast casserole should be eaten within 3 or 4 days. If you have a large quantity of leftover casserole, you can freeze the leftovers. The quality of a frozen egg casserole is best if eaten within a year.

What is the Best Way to Keep the Easy Overnight Breakfast Casserole Hot While Transporting?

Here’s a trick my husband had to use when he was taking a hot breakfast casserole to a function that was over an hour away. Use a paper bag! We wrapped the casserole in a couple of towels, put it in a paper bag, then closed the bag and hoped that it would work. It did! When my husband arrived at his destination, the casserole was still hot and toasty.

How do You Keep Egg Casserole from Falling?

With this recipe, there is little danger of it collapsing in the middle as some breakfast casseroles might. Since this casserole contains croutons, they don’t get as puffy as regular bread mixed with eggs. This breakfast casserole is a bit denser, which some people prefer. For a puffy egg casserole, you can prevent falling by cooking at a lower temperature, as with this recipe.

Can You Freeze Breakfast Casserole After Cooking?

Yes, breakfast casserole may be frozen. Just be sure to thaw in the refrigerator before reheating. Then you can follow the reheating methods noted above.

Do Egg Casseroles Freeze Well?

Breakfast casseroles do freeze well. I am a big fan of freezing things for later, and this easy overnight breakfast casserole recipe holds up in the freezer better than some of the more fluffy casserole varieties. You can put the casserole into a covered freezer container or you can wrap individual servings in foil and freeze.

Why Did my Casserole Dish Explode in the Oven?

This did not really happen to me, but this has happened to some people. No one wants an exploding casserole dish, especially if you have house guests. If you are using a glass casserole dish for this casserole ( I usually do), be careful about going straight from the refrigerator to the oven with the casserole dish. Here’s a casserole dish that claims to be safe from the freezer to the oven, and it even has a cover.

The chances of your casserole dish actually exploding due to the temperature change are slim, but here’s what to do to avoid this calamity. Take the casserole dish out of the refrigerator at the same time as you turn your oven on to heat. By the time your oven has reached the baking temperature for this recipe, your casserole will have warmed up slightly and you can safely place the dish in the oven.

How Can I Make This Casserole More Spicy?

Some people in my family are very fond of spiciness. To make this easy overnight breakfast casserole have even more of a spicy zing, you could try using spicy sausage. When you are browning the sausage with the onion in the skillet, add a hot pepper (seeded or not, depending on your spicy courage).

How Can I Make This Casserole Less Spicy?

If you want a very mild easy overnight breakfast casserole, omit the salsa. Add 1/2 cup of milk to the cream of mushroom soup instead. Be sure to stick with the regular sausage.

What Else Can I Add to this Breakfast Casserole?

I like to put sour cream on top of this casserole. Another flavorful topping is guacamole. You can always add in extra mushrooms when you are browning the sausage. It’s always a temptation to sneak in some extra vegetables somewhere, and dried kale flakes are a good choice, as I wrote about in my post about sneaking veggies into food.

Other Easy Breakfast Recipes

It’s always nice to have a few easy breakfasts in your menu rotation, especially when you have guests. One easy and delicious option is School Breakfast Pizza. For a camping trip, to feed a crowd, try making Super Simple Skillet Breakfast. Another popular choice is Easy Eggless Breakfast Casserole. These recipes are stress-free winners!

Make Ahead Recipes to the Rescue

In addition to make ahead breakfast casserole, I am also a huge fan of making meals ahead for dinner. If you know you are going to be having houseguests during the holidays, try this simple make ahead overnight breakfast casserole. For an easy make ahead dinner,make ahead freezer lasagna has come to my rescue many times, as well as make ahead mashed potatoes.

Are You Now Craving Easy Overnight Breakfast Casserole?

The savory goodness is calling my name. If you decide to try this recipe, I’d love to know what you like to serve it with. Did you serve it to houseguests to rave reviews? If you like what you’ve read today, please consider subscribingand becoming part of the Fluxing Well tribe. You will receive fresh ideas every week, plus access to a library of free printable resources, including a free cookbook filled with the best easy recipes from the Fluxing Well website.

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If you would like even more recipe ideas, consider following myEasy Recipes board on Pinterest. Have a fabulous day, and enjoy experiencing easy overnight breakfast casserole.

Lisa Mitchell is a wife, mom, and school librarian who likes to create and share recipes, often using fresh ingredients from her family’s small Pacific Northwest farm. To learn more about what this website has to offer, click on over to theWelcomepage.

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