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 and breakfast egg muffins, 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.
- Vegetables
- 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. It’s almost like the way we need an English muffin with our eggs benedict—to help soak up all that eggy goodness.
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. For healthy recipe ideas, see my complete list of 30+ healthy breakfast recipes. However, if you’re entertaining—or if you have several hungry teenagers in your house— you’ll love pairing 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
- Apple Cider French Toast
- 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
Description
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.
Ingredients
- 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
Instructions
- 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.
Notes
- 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.
- Special Tools (affiliate links): 9×13-inch Baking Dish or any 3–4-quart Oven-Safe Dish | Glass Mixing Bowls | Whisk
- 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.
Nutrition
- 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
I have made this twice. I use frozen potatoes and vegetables. Also a drizzle of maple syrup mixed with the sausage. Very easy and delicious. Prep it for the week and it stays good.
★★★★★
Made this as directed with breakfast sausage, hash browns, onion, green pepper, garlic, and spinach. Did not use Italian herbs. Everyone liked it, but we agreed that a can of green chilis would have made it perfect.
★★★★
I halved the recipe and it was fabulous. I also froze a leftover piece and it was great too.
★★★★★
This looks so good! I want to make this ahead of having my second baby next week, but just not sure the best way to prepare and freeze. Is it better to freeze before cooking or after cooking?
Hi Claire, congratulations to you! Either method works (outlined in the recipe notes), it really depends on how much cooking you’d like to do once thawed. If it’s easier, you could also bake, slice, and freeze individual slices to thaw as needed. Hope this helps!
Can you add rotel tomatoes to recipe
Hi Darlene, tomatoes would be a great add-in to this casserole, but Rotel tomatoes straight from the can may add a bit too much moisture. If you wish to try it, you may want to drain the excess liquid and gently pat the tomatoes dry before adding. Let us know if you try it!
Could I sub frozen brown rice for the frozen hash browns/bread?
Hi Cindy, I’m honestly not sure. I haven’t tried it before, so let me know if you do.
I thought it turned out well. People at the breakfast potluck liked it also. I made it into muffins for easy sharing. Thanks for the recipe!
Can I cook all the ingredients then freeze until ready to use?
Hi Marian, sure can—see recipe Notes for freezing details. Enjoy!
Delicious and so versatile. A keeper! One question on reheating the baked frozen casserole: your notes say to cover with plastic wrap and aluminum foil when freezing then thaw it covered in the refrigerator. The notes then say to remove the plastic wrap layer and bake. Do I bake it with the aluminum foil on?
Thanks!
Hi Liz, we bake it completely uncovered, but if you find it’s browning too quickly you can bake it with the aluminum foil on part way through. So glad you enjoyed this one!
I made this for a work potluck and it was a hit! I’d like to make it into individual breakfast muffins for a bake sale… any suggestions on cook time and temperature? Thanks in advance!
★★★★★
Hi Kdub, you can definitely make this as individual servings in a muffin tin.
Would diced green chilis work in this recipe? Full disclosure, I haven’t made this recipe yet, but wondering if this addition would elevate the recipe OR make it a flop?! Thanks for the help!
Hi BJG, if you enjoy a bit of spice, we can’t see why that wouldn’t work. Let us know if you try it!
We all agreed that a can of diced green chilis would be perfect in this.
★★★★
We loved this recipe so easy and delicious!!! I love the way you can interchange veggies, meats and cheeses. Thanks for adding all the great ideas with the recipe.
★★★★★
I asked earlier if I could halve the recipe before rereading the notes and seeing the comments! So, I just want to say that it turned out beautifully.
I made this for brunch today and it was a hit! People went back for seconds. I didn’t include the spinach but it was still delicious. I will be making this again for sure! Thank you for sharing it.
★★★★★
I am wondering if you can freeze this casserole or any of your breakfast style casseroles?
Yes, absolutely! See recipe Notes for details.
Hello. Could I halve this recipe and, if so, what size of pan. It looks delicious.
Hi Carol Ann, you can halve this recipe for the 8-inch square pan. We’re unsure of the exact bake time, but guessing around 30 minutes, however that depends on all the add-ins. Keep a close eye on it. Even after thawing, the bake time should be similar.
Looks really good and I plan to make this soon for a brunch somewhere else. 12 eggs is a lot though! Can I just do 6 and the rest either tofu or Just Egg
I’m pescetarian so I plan on using plant-based sausages. Thank you in advance!
Hi Michelle, we haven’t tested this recipe with egg alternatives, so we’re unsure of the results. Let us know if you do give it a try.
A co-worker brought this to work and I loved it so much that I asked for the recipe and treated relatives to it this morning on while visiting out of state. It makes a lot of food and re-heats well. This recipe is a keeper!
This recipe is absolutely delicious!!! I love the italian touch and I think next time I will add some fresh basil. I served this at my neighborhood Coffee Chat gathering and it was a big hit.
Hi Sally and Team,
I made this on Easter Monday for the grandkids. They really enjoyed it; in fact, Ginger kept sneaking into the kitchen for the little bit that was left.
As I had prepared the night before, I wasn’t sure whether I was supposed to turn it over because the moisture had not penetrated the top layer. Still, it went over well.
Love this breakfast casserole, after prepping, how many days can it be in refrigerator before baking?
Hi Sally, up to 24 hours.
my name is peter sciscente am a chef in an old folks hoome and on easter i made your cassorole with veg. chicken strips meat loaf strips eggs cheese bakeed in oven bacon patotoes mini muffins they where every happy it was great thank you so much
★★★★★
Wow! This is SO YUM! I used frozen tater tots instead of bread because I had some on hand. They worked great! This is a complete breakfast in one dish. And it’s even better the next day as left overs. I will definitely be making this for my next potluck breakfast…can’t wait to try it with sourdough bread. Thank you for another great recipe, Sally!
★★★★★
Easy and tasty!!!
★★★★★
I made this a couple weeks ago for our big family brunch. Everyone loved it so much, there wasn’t a bite left. I’m making two tonight for Easter Brunch tomorrow with family.
This was fabulous! Because I used fresh challah, I did toast the cubes as suggested, and used a mix of red and green peppers – so pretty! Also, since it’s just the two of us, I halved the recipe and cooked it in an 8” square Corning Ware dish (instead of 9” as recommended in the recipe) – worked out just fine.
★★★★★
Can you use shredded frozen hashbrowns or does it have to be the diced ones?
Hi Erin, Some readers have used shredded hash browns with success. We usually use the diced frozen hash brown potatoes mentioned in the Notes.
I made this for the first time and it’s going on the keeper list (along with many other recipes from your wonderful site)! Thank you, Sally! Beautiful blend of flavours, textures, and colours. I halved the recipe exactly and added half a cup of bite-sized pieces of asparagus to the mix of veg, and used spicy Italian sausage. I agree with you, good sourdough is essential. Perfection.
★★★★★
Think I could double it in a larger lasagna pan? I have 16 people to feed. Thanks!
I followed the recipe exactly to bring to the office to share this morning, and the pan was cleaned out in no time! Several people came back for seconds and asked me for the recipe. It was really easy and really tasty. I definitely plan on keeping this recipe in my pocket for special breakfast occasions (or anytime I’m craving something savory and delicious)!
★★★★★
I really liked this recipe. I used potatoes, a spicier sausage and an extra clove of garlic but otherwise followed the recipe as is. It did take a bit longer to cook in my oven so I just watched it until it was set in the middle.
★★★★
I served this at a family brunch today. I used potatoes instead of bread since we had other breaded items on the menu. Maybe it would have better with bread but we were all underwhelmed. Was disappointed as I was looking forward to adding it to my repertoire. Will go back to my other tried and true egg casseroles.
★★
This recipe is great! Do you think I can refrigerate it longer than 24 hours (32) without it getting soggy?
Hi Megan, the casserole will start to get soggy after 24 hours. For longer storage, see recipe Notes for freezing instructions.
Can this be cooked in the crockpot/instantpot?
Hi Tina, we haven’t tested it, but let us know if you try anything!