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 sausage & herb stuffing, breakfast strata, 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, whole wheat 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
Wonderful recipe!! I made it yesterday for the first time and the results were even better than I anticipated. I made only change and subbed broccoli for the spinach. I used sour dough crusty bread and the texture was perfect. Almost like a bread pudding. I made it for my Physical Therapy group and they loved it. It’s a keeper!
Thank you!!
I’ve made the Egg and Sausage Casserole for years and years…but for a special Sunday after church I’ll make your vegetable version. I’ll make different combinations of the veggies to offer choices. Do you think it will work as well in foil pans?? I hope so!! Can’t wait!
Hi Leslee, we haven’t tested it in foil pans, but I don’t see why it wouldn’t work. Hope they are a big hit!
Easy Make-Ahead Breakfast Casserole.
I am making this casserole for my physical therapy office. I prefer to make it in a disposable aluminum pan for convenience for them. Any concerns regarding this egg mixture sitting in an aluminum pan over night in the fridge. And will it bake up alright in an aluminum pan? Thank you for your help.
Hi Carmelynn, it should be fine!
Thank you,
I’ll let you know how it turns out. I’m sure excellent as all of your recipes do!!
I baked it in a 9×13 foil pan. The results were perfect.
Is it important to let the casserole sit overnight if using potatoes as the base? Not sure if the frozen potatoes will discolor.
Hi Nancy! No, you can just refrigerate for half an hour or so while the oven preheats. Enjoy!
I’ve made this twice this week. It was meant for the freezer the second time but you know it didn’t make it there. We ate ALL of it. Highly recommended. We used Mexican chorizo for the pork sausage.
Your recipes are always the best! Even my picky kids liked this. Mine did develop a little “crust” along the bottom and edges, just where the egg was a little more tough. That was my kids only complaint. Do I just need to bake a little less to prevent this?
Hi Natasha, we’re so glad it was a hit! A little crust can be normal, but it sounds like it might have been overbaked. You can try reducing the bake time by just a few minutes next time and that should help.
Has anyone tried using sweet potatoes as a base? Would they work like potatoes or bread?
Hi Anna, we can’t see not! You can follow the directions for using fresh potatoes: “peel and dice fresh potatoes, but you’ll need to quickly cook them on the skillet for 10 minutes before using in this dish.”
How many helpings do you think one casserole will make?
Hi Celeste, we get 12 servings from this casserole.
Could I make this using the simply potato hashbrowns that are not frozen?
Definitely!
I had my doubts, as I had no good bread available. However, I DID have an unopened bag of large Caesar croutons. I used those, and sautéed breakfast ham, onions, peppers, and mushrooms. It was SO GOOD. I only refrigerated for 90 min after adding the egg mixture before baking, but it still turned out just perfectly.
Can I cook this in a crockpot after I let it sit in the fridge overnight to soak? If so, for how long should I cook it? Thanks!
Hi Tyler, we don’t recommend cooking this recipe in a crock pot.
Super easy and lots of wiggle room to add your favorite veggies! I’ve been making one of these just about every week so far this year for a quick and balanced breakfast.
Made this recipe and added hash browns. Absolutely perfect I cooked mine covered with foil for 30 minutes and 15 minutes no foil.
I plan to make this for company. Maybe you can help me troubleshoot in advance. My egg casseroles tend to come out with a rubbery egg layer on top. Do you know what I might be doing incorrectly?
Hi Jess, We are happy to help! Sometimes eggs can be rubbery from over-baking. It can also happen if there is too much moisture in your eggs, but pre-cooking all of add ins helps reduce the moisture significantly.
Can I double this recipe? How would that affect the bake time?
Hi Lisa, you can double the recipe for a larger pan. Many readers have done so with success. We’re unsure of the exact bake time for a larger pan, though. You could also double it and then divide between two 9×13-inch pans. Let us know what you try!
This was delicious! In order to make it gluten free, I used a layer of gluten free stuffing mix (I used Gillian’s) which added a nicely seasoned base. I used the entire package but will only use half in the future as I thought it was too much bread in the end. The reviews were excellent!!
Sally,
I have some frozen croissants that we put in the freezer before they expired, would these be ok to use in this recipe? Should I toast them slightly or dry them out by baking? Thank you for helping!
Hi Christine, we haven’t tested it, but it should probably be fine. Definitely toast the croissant pieces first!
Spectacular tasting, and I had so much fun with it. It was the first time I made an egg casserole and froze for two weeks before baking. Used gluten-free bread for the IGF people. It turned out perfect–thank you!
My go-to Breakfast casserole now.
This looks delicious! Would plant based meat crumbles work for this recipe?
Hi Eileen, those should be fine!
I made this for New Year’s Day and it was excellent! Thank you!
Great way to use some leftover Christmas ham
I prepared this through step 5 and and put it in the freezer ithen I took it out of the freezer and put it in the refrigerator 4 days ago. Is it still ok to bake it and serve it?
Hi Constance, it’s hard to say, but always do what you’re comfortable with!
Can you eliminate bread/potatoes all together?
Hi Kristie, for an egg-based dish without bread/potatoes, we’d recommend a quiche or egg frittata instead.
This was perfection! Didn’t have crusty bread so tore up some cinnamon bagels instead.
Love that this recipe was not too heavy and full of flavor.
Hi Sally – I made your recipe for my family’s Christmas breakfast this morning, and made it exactly as written, except I included “Impossible” soysage, and cooked the same way. I used toasted croissants as my bread. It was a big hit! Thanks!! A keeper. 🙂
I made this on Christmas Eve and it was the perfect breakfast on Christmas morning! I went with more of a southwestern vibe and used onions, bell peppers and green chilis as my veggies and it was delicious!
Made this for Christmas Day brunch – fabulous! Tweaked just a bit omitting the mushrooms since daughter is not a fan, and doubling up on the spinach. Also sprinkled a little extra cheese on top. The flavors were perfect as was the consistency. WIll definitely be making again!
I made the meat portion the previous due to time issues. Also, I split the recipe into two separate casserole dishes. I think if I make this again, I may add the meat mixture to the egg mixture to be sure each dish is the same. I haven’t cooked it yet so I can’t comment on the result. Giving one to a friend. Will see. Thanks for reading my review.