Each slice of this easy egg breakfast casserole is thick, flavorful, and satisfying; plus, the recipe is an incredibly convenient breakfast choice since it’s make-ahead and infinitely adaptable. Like quiche, you can use your favorite seasonings and cheeses, vegetables like peppers and mushrooms, meats like sausage or bacon, or you can make it vegetarian. The best part is that you can assemble this dish ahead of time so breakfast is a breeze in the morning!
Breakfast casserole is an all-in-one hearty meal that can be made ahead of time, feeds a crowd, reheats well, and makes great leftovers. My family devours it. For all these reasons and more, I’ve made it nearly 100x (no exaggeration there) for breakfast, brunch, and, yes, dinner. It’s one of my favorite Easter brunch recipes to serve each year, too.
I originally published this recipe in 2015 and have simplified it over the years. Let me show you how it comes together so you too can experience this crowd-pleasing superhero meal.
This Easy Breakfast Casserole Is:
- Adaptable to whatever vegetables, meats, cheeses, and herbs you have on hand.
- Easy to make ahead of time.
- Quick to throw together.
- Great as a quick weekday meal or a lavish weekend or holiday brunch.
- Excellent for entertaining a crowd.
- Made with some bread to soak up moisture, but potatoes work too!
- Ready for your favorite egg toppings like salsa, pico de gallo, green onion, cilantro, parsley, avocado, everything bagel seasoning, hot sauce, etc.
4 Main Components
When gathering ingredients for this recipe, I like to think of it as having 4 separate components. From there, you can have fun with variations.
- Meat (or extra vegetables)
- Starch for soaking up moisture
- Egg, cheese, & milk mixture
Here Are the Endless Add-ins & Flavor Options
- Vegetables: Select which vegetables you’d like in the dish. Generally, the most popular with guests is bell peppers, spinach, and mushrooms. But I’ve also made this with broccoli/peppers, kale/mushrooms, and spinach/zucchini. Try to stick to 3–4 cups of vegetables total. Cook the vegetables down with some flavor-enhancing onion and garlic.
- Meat: Guests usually prefer meat in the casserole, so I add sausage. Or try using ground turkey, chopped bacon, ground beef, or ground chicken. I usually purchase uncooked sausage for this and brown it with some dried rosemary or Italian seasoning to give it a little extra flavor, but that is optional. If the meat you’re using is pre-cooked, such as chopped ham or shredded chicken, you can mix it with the cooked vegetable mixture before layering it into the dish.
- Starch: Like when making breakfast strata, sausage stuffing, and French toast casserole, the bread should be slightly stale so it can soak up moisture. Crusty sourdough is FANTASTIC here. You can also use homemade artisan bread, seeded oat bread, a loaf of French bread, crusty baguette, biscuits, bagels or homemade bagels, or even day-old croissants (have you tried homemade croissants?!). To make it gluten free, use gluten-free bread or potatoes.
- Eggs, milk, & cheese: Whisk a dozen eggs with a little half-and-half or milk and stir in some shredded cheese. Like the vegetables and meat, use whatever cheeses you like best, such as sharp cheddar, pepper jack, feta, and/or smoked gouda.
Variations: One of my favorite variations of this recipe is everything bagel breakfast casserole. It’s a BIG HIT and consistently gets rave reviews. Or try my different method/recipe for biscuit breakfast casserole with homemade biscuits baked right on top.
Can I Use Potatoes?
Yes, you can replace the bread with diced hash brown potatoes—the kind you find in the freezer section of the grocery store. Guests have *loved* this version. Use about 3 cups (around 380g) of hash browns in place of the bread. You could also peel and dice fresh potatoes, but you’ll need to quickly cook them on the skillet for 10 minutes before using in this dish.
Another wonderful make ahead option with fresh potatoes is this ham and potato casserole that is egg free, but just as delicious.
Do I Have to Use Bread?
Bread or potatoes, yes. Besides eggs, bread is the main ingredient. To avoid a spongey, wet dish, this breakfast casserole needs structure at the bottom. You see, when eggs bake, they release a lot of liquid. Chunks of crusty bread (or hash brown potatoes) soak up some liquid so the casserole is chunky and textured, not flat and wet. If you’re looking for something without this starchy addition, crustless vegetable quiche or an easy frittata are great options.
In Pictures: How to Make Breakfast Casserole
First, place the pieces of bread (or potatoes) in the bottom of a greased 9×13-inch or any 3–4-quart oven-safe dish. I usually use (affiliate links) this glass pan or the pictured red ruffled baking dish, which comes in a set with other sizes—definitely a splurge, but I’ve found the quality to be excellent. Showing you the bread scattered in the pan as well as the optional potato substitution:
Set that aside and pre-cook your vegetables and meat (if the meat is not cooked already). You can do this all in 1 big skillet on the stove, adding onion, garlic, and optional herbs like dried rosemary or your favorite seasoning blend. As that’s sizzling on the stove, whisk the eggs, milk, and cheese together:
Now it’s time to assemble, and I’ve made this process a lot easier over the years. Spoon all of the vegetables/meat mixture on top of the bread. Pour the egg mixture all over that:
Success Tip: Refrigerate Overnight
At this point, you can either bake it right away or refrigerate the casserole overnight and for up to 24 hours. During this time, the flavors mingle together and the bread has a chance to soak up some of the liquid and flavor. Wake up and all you have to do is slide it into the oven. If you’re in a rush, I do recommend at least 30 minutes in the refrigerator before baking, if you can spare it!
Bake until the edges are golden brown. Because it’s so egg heavy, the casserole puffs up in the oven like a cheesecake and then sinks back down as it cools. Cool for 5–10 minutes before slicing and serving.
What to Serve With Breakfast Casserole
For side dishes, fresh fruit and yogurt are light, simple, and quick. However, if you’re entertaining—or if you have several hungry teenagers in your house—pair this breakfast casserole with:
- Easy Cinnamon Rolls
- Slow Cooker Cinnamon Rolls
- Pumpkin Cinnamon Rolls or Pumpkin Crumb Cake
- Banana Muffins or Blueberry Muffins
- Baked Oatmeal
- Sour Cream Coffee Cake
- Banana Bread or Zucchini Bread
- Dark Chocolate Raspberry Coffee Cake, a Cinnamon Roll Wreath, or Cranberry Cake (great options around the holidays)
Your brunch guests will be beyond satisfied. Yes, even the teenagers!Print
Easy Make-Ahead Breakfast Casserole
- Prep Time: 20 minutes
- Cook Time: 45 minutes
- Total Time: 1 hour, 30 minutes
- Yield: serves 12
- Category: Breakfast
- Method: Cooking
- Cuisine: American
This easy breakfast casserole is infinitely adaptable and you can find variations and suggestions in the recipe Notes below. The version written below with sausage, mushrooms, bell peppers, spinach, and cheddar cheese is generally the most popular with guests. You can assemble the entire dish and refrigerate for up to 24 hours before baking.
- 4 cups (175g or 6 oz) cubes of crusty bread*
- 1 teaspoon olive oil
- 1 pound ground pork sausage, casings removed*
- 1 teaspoon dried rosemary or Italian seasoning, optional
- 3/4 cup (100g) chopped yellow onion (1/2 of a large onion)
- 2 garlic cloves, minced
- 2 cups (275g or 9–10 oz) chopped bell peppers
- 1 cup (100g or 3 oz) sliced mushrooms
- 1 cup roughly chopped fresh spinach
- 12 large eggs
- 1/4 teaspoon salt
- 1/8 teaspoon freshly ground black pepper
- 2/3 cup (160ml) milk or half-and-half*
- 1 cup (100g or 3.5 oz.) shredded cheddar cheese
- optional garnish: green onion and/or chopped parsley
- Grease a 9×13-inch or any 3–4-quart oven-safe dish. Arrange bread cubes in an even layer in bottom of pan.
- Heat olive oil in a large skillet over medium heat. Add sausage and rosemary/Italian seasoning, if using, and break up the sausage into bite-size pieces with a wooden spoon or rubber spatula as it begins to cook. Add the onion, garlic, peppers, mushrooms, and spinach and cook until everything has slightly softened and sausage is mostly cooked through, about 5–6 minutes.
- Remove sausage and vegetable mixture from heat and spread in an even layer on top of bread.
- Whisk the eggs, salt, pepper, milk, and cheese together. Evenly pour over sausage/vegetable mixture. Add another sprinkle of salt and pepper on top.
- Cover casserole with plastic wrap or aluminum foil and refrigerate for at least 30 minutes and up to 24 hours. (When ready to bake, allow to sit at room temperature for 10–15 minutes as oven preheats.)
- Preheat the oven to 375°F (191°C). Bake the casserole, uncovered, until the top is golden, edges are crisp, and a toothpick inserted in the center comes out clean, about 40–45 minutes.
- Cool for 10 minutes, then slice and serve.
- Leftovers keep well in the refrigerator for up to 5 days. Reheat in the microwave to your liking.
- Make Ahead Instructions: This is an excellent make-ahead recipe because you can assemble it before baking up to 24 hours in advance. See step 5. You can also cook the sausage and vegetable mixture up to 24 hours in advance, cover and refrigerate until ready to use.
- Freezing & Reheating Instructions: To freeze, prepare and assemble through step 5, cover with plastic wrap, then a layer of aluminum foil, and freeze for up to 3 months. Thaw overnight in the refrigerator, and then bring to room temperature before baking as directed. You can also freeze the baked casserole for up to 3 months and when doing that, I suggest baking it in a disposable aluminum pan. Cool completely, cover with plastic wrap, then a layer of aluminum foil. When ready to eat, thaw it for about 24 hours (covered) in the refrigerator, remove the plastic wrap layer, then bake in a 350°F (177°C) oven for 25–30 minutes.
- Bread: Crusty sourdough is fantastic in this recipe, or use any crusty, hearty bread. The crustier or more stale, the better. If your bread is fresh and/or flimsy, cut into cubes and bake on a baking sheet in a 300°F (149°C) oven for 10 minutes. It’ll be slightly crisp and ready to use in this recipe. No need to wait for the bread to cool before layering into the baking dish.
- Using Potatoes Instead of Bread: You can replace the bread with diced hash brown potatoes—the kind you find in the freezer section of the grocery store. Use about 3 cups (around 380g) of frozen hash brown potatoes, no need to thaw. You could also peel and dice fresh potatoes, but you’ll need to quickly cook/brown them on a skillet with 1 Tablespoon olive oil over medium heat for 10 minutes before using.
- Sausage or Other Meat: If using pre-cooked sausage links or ham, cut into slices/chunks, and there is no need to cook either. Simply stir into the pre-cooked vegetables before layering into the dish. You can replace the sausage with ground turkey, beef, or chicken—simply pre-cook with the vegetables according to the instructions. If using bacon, I recommend reducing to 1/2 pound and cutting into bite-size pieces. Cook separately from the vegetables until browned. Drain, then mix with the vegetables before layering into the dish.
- Other Vegetables: Feel free to replace all or some of the bell peppers, mushrooms, and spinach with other vegetables such as chopped broccoli, sliced zucchini or squash, or kale. Pre-cook as directed.
- Vegetarian Option: You can leave out the meat and replace with another 1 cup of vegetables.
- Milk: For the richest, heartiest texture, I recommend half-and-half or whole milk. You can use lower-fat milk or dairy-free milk if desired.
- Cheese: I usually use a blend of regular and sharp white cheddar cheeses. Use whatever cheeses you like best, such as pepper jack, feta cheese, Swiss, and/or smoked gouda.
- Half Recipe: You can halve this recipe by halving all of the ingredients and using a 9×9-inch square pan. Bake time is slightly shorter, about 32–36 minutes.
- Serving Size:
- Calories: 212
- Sugar: 3.1 g
- Sodium: 343 mg
- Fat: 12.8 g
- Carbohydrates: 11.2 g
- Protein: 12.5 g
- Cholesterol: 205.4 mg
Keywords: breakfast casserole, overnight breakfast casserole
Reader Comments & Reviews
This looks delicious and I can’t wait to make it for the fam! Curious if shredded hash browns would work as a replacement for the bread, or would you only recommend diced? Thank you!
Thank you! Some readers have used shredded hash browns with success. I usually use the diced frozen hash brown potatoes mentioned in the Notes.
this looks delicious and very adaptable to ingredients on hand…We have a family member who is very lactose intolerant ..can the cheese just be omitted ?? Use nut milk ? thanks so much
Hi Doris! You can leave the cheese out and use a dairy free milk. You may even be able to find a dairy-free cheese replacement to add more flavor. Let us know what you try!
I made this Christmas Eve for Christmas morning and it was so delicious! I used the frozen home fries instead of bread and cooked a few slices of bacon to sprinkle in the mix in addition to the sausage and my family loved it! I think everyone had seconds! This is a must now for every Christmas morning!
I made this for Christmas morning. It was a hit! Which was a relief, since we were staying with family I had forgotten to bring the food I had bought to cook for this meal. I used latkes and homemade bread, roasted veggies, and a cheeseball, all leftover from Christmas Eve dinner, with just a little added cheese. It was so delicious, and saved me from having to run out to the store Christmas morning.
Made this for Christmas morning. Delicious! Where I am there was just a 10×15, so I just added more bread, three more eggs, more spinach, cheese and a bit more milk.
Used the frozen potatoes instead of bread as was mentioned in the notes and this was such a hit. Making it Christmas morning.
Hi! I’m going to use readymade frozen potatoes. Should I use the frozen potatoes that are uncooked? And do I need to cook them?
Hi Sarah, you can use frozen potatoes, and no need to thaw or cook them first. They will cook in the casserole. Enjoy!
Can I skip meat? If so, do I have to modify anything such as cooking time / temp?
Absolutely! See the recipe Note about the meatless option. Same bake time. Feel free to add more vegetables.
Hi , I was going to make the Breakfast Strata but then this one came up today. I see the concept is the same but the proportions are quite different (less bread and dairy and more eggs). How would you differentiate these two: they both say serves 10-12? I would leave out the meat in both. Thanks
Hi Allison, The strata is a type of breakfast casserole. The strata has twice the amount of bread and less eggs, so it has more structure and more texture. You can leave the meat out of both recipes.
Want to make this recipe for Christmas morning, but will not have time to put it together the day before. Can it be put together and stored in the fridge for more than 24 hours? Thx!
Hi Jen! The casserole will start to get soggy after 24 hours.
It seems like to avoid it from being soggy, add the wet ingredients at least 30 minutes before you are ready to bake. You can mix those and just put it in a container. HTH!
Thank you! (I’m making it now and didn’t want to have it turn out too dry if I drained it!) Have a good Christmas
I’m making this recipe using sausage and the other basic ingredients. Do I need to drain after cooking? I’m thinking the sausage, fresh mushrooms, and spinach might make things too runny?
Hi Jenny, if it seems especially “greasy,” you can definitely drain it before adding. Hope you enjoy it!
Hello! Can’t wait to make this! If I use the frozen hash browns, can I still make it ahead the night before and let it soak or only put it in the fridge for 30 min before baking if I use the frozen hash browns over bread?
Hi Erin, you can still make this the night before is using frozen hash browns. Enjoy!
Sally, I would like to try this recipe (freeze before baking) but in single servings of 4 oz. foil ramekin cups. Any suggestions on the baking temp and time for this version?
Hi Erica, same bake temperature, but we’re unsure of the exact bake time. It will be a bit less, but keep a close eye on them. Great idea to make them in single servings!
Hi Sally. Your recipe is clearly kitchen tested and accurate. I followed it very closely and the outcome was delightful. And for some reason the casserole tasted even better the following day! Many thanks!
I love this recipe and have made it lots of times for my family. I’m now needing to go gluten free. Can I substitute gluten free bread for the bread?
Hi Bev, absolutely, you can use your favorite gluten-free bread here.
Delicious! Hosted a brunch and everyone just loved it!
This was delicious! I used cubed croissant bread in place of the sourdough and frozen spinach (thawed and squeezed to remove the extra moisture). Looking forward to making this again!
How long do you bake it for?
Hi Renee, see Step 6 — Preheat the oven to 375°F (191°C). Bake the casserole, uncovered, until the top is golden, edges are crisp, and a toothpick inserted in the center comes out clean, about 40–45 minutes.
My family loves this recipe and I’ve made it several times. Can this casserole be made with egg whites for a lower cholesterol versions?
Hi Nancy, We haven’t tested this recipe with only egg whites. We’re unsure of the exact amount that would be best – let us know if you try it!
This was perfect for serving my in-laws when they stayed over. I prepped it the evening before, then baked in the morning. Absolutely perfect!
Made this for my 10 and 12 year old sons. They’re not crazy about lots of veggies. I made this with potatoes, red and yellow bell peppers, spinach and chopped broccoli and Italian sausage. They LOVED it! I made two batches, portioned into small squares and froze. This will make great breakfasts on busy mornings when we have to get out the door for school. Thanks for another great recipe that my family loves!
So happy to hear that this breakfast casserole was a hit with your family, Kelli!
I’m going to make this as a meal prep breakfast for the week. I might try tater-tots instead of bread/hashbrown. That ought to work I imagine?
Hi Shea, it works just fine.
Your recipe looks amazing! I know my family would love it. Unfortunately, I am not an egg person so am wondering if there is a way to substitute more heavy cream in lieu of some of those eggs? It would be more of a custardy type of casserole but not sure how that would affect your dish. Any thoughts?
I love so many of your recipes, THANK YOU!!
Hi Vicki, the eggs provide crucial structure here and it would take a bit of recipe testing to try a replacement/different amount. Our breakfast strata and bagel breakfast casserole have fewer eggs (9 each) if you’d like to give either of those a try!
I hosted my family for the first time in our new house and made breakfast for dinner using this recipe and Sally’s banana bread recipe. Both were HUGE hits! I will be making them again!
Could you use potatoes AND bread?
Absolutely! I would use 2 cups of bread cubes and 1.5 cups of potatoes (so, half of each).
I make a recipe really similar to this and use big croutons in place of the bread and it adds so much flavor!!
I do the same. I use salad croutons, and bake in muffin tins instead of a pan. Freeze them for individual take along breakfast after warming in the microwave or toaster oven. I love to pack these when we leave in the early morning for a trip. We can eat on the road, with a travel mug of coffee or juice!
Hi Marianne! Love this idea. What cook time and temp do you do for breakfast muffins?
I am definitely going to try this, thank you!
I am wondering if you think it would be ok to use frozen spinach (thawed and water squeezed out) instead of fresh spinach?
Hi NK, that should work, especially since the spinach will be sauteed with the other vegetables. Hope it’s a hit!
Thank you! 🙂
So do you use 4 cups of salad croutons?
Sally, this sounds wonderful, but can I halve the recipe.?My oven currently does not work, so I would have to use my KitchenAid toaster oven.
Can’t wait to make this, as I am a vegetarian always looking for new recipes.
Absolutely! See recipe note. I recommend a 9×9 inch square pan.
Thanks so much for responding Sally.
Great breakfast casserole! And, yes, you do need all those eggs! Thank you for sharing a version that doesn’t skimp on the eggs, Sally! I have made this with many leftover meats and veggies, and, added whatever cheese I have on hand, and it’s always delicious!
If I use potatoes, should I cook them first?
Hi Vicki, if you are not using frozen hashbrown potatoes, I recommend a quick cook, yes. See specific details in the recipe Note.
Made this last night and baked, this morning, for family. Thumbs up around the table. So easy and delicious.
Could it be made without bread or potatoes for it to be keto friendly. Thank you
Hi Trish, not this recipe. You may enjoy this crustless vegetable quiche instead though.
Approximately how many cups of bread cubes do I need? I want to use Sourdough bread but the loaf is not large. I am uncertain if 4 slices will be enough. THANKS!!
You need 4 cups (175g or 6 oz). Sourdough is a favorite for this recipe!
I’d like to serve this the morning after thanksgiving but don’t want to worry about making it on thanksgiving day. Can I make it, bake it and then freeze it, like…3 days before?
Hi Caryl, yes, you can freeze the completely baked casserole. See recipe Notes for thawing and reheating details.